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by Lt Cdr Geoffrey B Mason RN (Rtd) (c) 2006

HMS EMPEROR (D 98) - Ruler-class Escort Aircraft Carrier
including Convoy Escort Movements

HMS Queen, sister ship (Navy Photos/Mark Teadham, click to enlarge) return to Contents List 

RULER-Class Escort Aircraft Carrier obtained under US/UK Lend Lease Agreement. A mercantile which was under construction by Seattle-Tacoma Shipbuilding Corporation at Seattle and was  requisitioned by the US Navy for completion as an escort aircraft carrier (CVE34) to be named  USS PYBUS. She was laid down on 23rd June 1942 and launched on 7th October that year. Build was completed by Puget  Sound Navy Yard on 31st May 1943 and entered US Navy service.. On 6th August 1943 after passage to the east coast this ship was transferred to the RN and commissioned as HMS EMPEROR. This name was introduced in 1857 for a Paddle-Yacht purchased for RN service and sold in 1860. It was again used in WW1 for a requisitioned Trawler. Selected instead of STINGER for a CVE built in the USA but as that ship was retained by the US Navy and became USS NASSAU BAY the name was given for the third time to this later CVE being transferred. US Navy radar outfits were fitted during build of the ship.


B a t t le    H o n o u r s

ATLANTIC 1943-44 - NORWAY  1944 - AEGEAN  1944 - NORMANDY  1944 - SOUTH FRANCE 1944  - MALAYA  1945 - EAST INDIES 1945 - BURMA  1945

 H e r a l d i c   D a t a

Badge: On a Field Blue, a Golphe (Roundel), rayed and Gold,  thereon an

Emperor's  crown Proper.



D e t a i l s   o f   W a r   S e r v i c e


(for more ship information, go to Naval History Homepage and type name in Site Search



1 9 4 3


May                        Contractors trials and commissioning.

                31st         Build completion and entered US Navy service.


July                         Passage to East coast of USA as USS PYBUS



                6th          Transferred to Royal Navy and commissioned as HMS EMPEROR.

                                Passage to Clyde

                                (Note: On 20th August with Convoy HX253 to be confirmed


                3rd          Arrived in Clyde.

                                (Note: HX253 arrived in Liverpool on 4tt September)

                7th          Taken in hand at Belfast for modification to suit deployment for RN service.

                                (Note: This included modification to petrol supply system carried out in all US

                                built CVE following loss of HM Escort Carrier DASHER.)


November              Under modification

to                            On completion of post refit trials embarked 20 HELLCAT aircraft and personnel

December              of 800 and 804 squadrons.


1 9 4 4


January                  Carried out work-up for operational service in Clyde

                                (Note: Deployment in Western Approaches command to be confirmed.)


February                Atlantic deployment in continuation.

                                (Note: One source records one complete Atlantic passage to Norfolk and return

                                Use of convoy defence and transport of aircraft to be confirmed.)


March                    Nominated for Home Fleet service

                18th        Passage to Scapa Flow on release from Atlantic convoy defence.

                30th        Deployed with HM Escort Carriers SEARCHER, PURSUER and FENCER and ships of Home

                                Fleet to provide cover for passage of Russian Convoy JW58 and to carry out attack on the

                                German battleship TIRPITZ in Altenfjord, Norway (Operation TUNGSTEN)

                                (Note: Home Fleet ships included HM Battleship ANSON, HM Aircraft Carriers FURIOUS

                                and VICTORIOUS, HM Cruisers BELFAST, ROYALIST, SHEFFIELD and JAMAICA

                                with screen of 14 Fleet Destroyers.

                                For details of all Russian Convoy operations and attacks on TIRPITZ see CONVOYS TO

                                RUSSIA by RA Ruegg, THE RUSSIAN CONVOYS by B Schoefield, ARCTIC

                                CONVOYS by R Woodman and CONVOY! by P Kemp.)


April                       Home Fleet TUNGSTEN deployment in continuation.

                3rd          Detached from covering duty with HMS ANSON, HMS FURIOUS, HMS VICTORIOUS,

                                HM Escort Aircraft Carriers PURSUER, SEARCHER, STRIKER three cruisers and screen

                                of five destroyers to carry out attacks on TIRPITZ.

                                Provided air cover during bombing attacks carried out by HMS VICTORIOUS aircraft.

                                (Note: 14 hits were obtained and battleship damage required four weeks repair.)

                5th          Return passage to Scapa Flow with Home Fleet ships.

                21st         Sailed from Scapa Flow with HMS ANSON, HMS VICTORIOUS, HMS FURIOUS, HMS

                                SEARCHER, HMS STRIKER and HMS PURSUER with Home Fleet cruisers and destroyers

                                to carry out further air attacks on TIRPITZ (Operation PLANET)

                24th        Operation delayed by weather conditions.

                25th        Further delay due to weather made cancellation necessary.

                26th        Embarked aircraft carried out attacks on Norwegian coastal shipping in Bodo area.

                                (Operation RIDGE ABLE. Three mercantiles sunk and another damaged.)


May                        Home Fleet duties in continuation.

                8th          Deployed with HMS SEARCHER and HMS STRIKER to carry out attacks in N.Kristiansund

                                area (Operation HOOPS)

                                (Note: Five enemy aircraft were destroyed for loss of two HELLCAT.

                                Patrol Vessel V5704 damaged and ships in convoy.)

                14th        Deployed with HMS STRIKER covered by HM Cruisers SHEFFIELD and ROYALIST with a

                to            screen of 6 Home Fleet destroyers to carry out attacks on shipping at Rorvik and

                15th        Stadlandet. No sinkings reported. (Operations POTLUCK ABLE and BAKER )

                16th        Returned to Scapa Flow with Home Fleet ships.

                20th        Resumed Western Approaches duties.

                23rd        Deployed to provide air cover for passage of outward joint convoy OS78/KMS52

                to            and inward joint Convoy SL158/MKS49 during Atlantic passages



June                        On release from Atlantic escort took passage to join HMS TRACKER and HMS PURSUER

                                in SW Approaches to intercept U-Boats attempting to attack allied invasion convoys to

                                landing beaches in Normandy,

                                (Operation NEPTUNE - For details of naval activities prior to and during allied landings see

                                OPERATION NEPTUNE by K Edwards and LANDINGS IN NORMANDY, JUNE 1944


                                Resumed Atlantic convoy defence duties on release from NEPTUNE.

                18th        Squadron 804 merged with Squadron 800 to form single unit.


July                         Nominated for service in Mediterranean and took passage to Malta.

                                (Note: WALRUS aircraft from 700 Squadron embarked.)

                                Passage to Mediterranean

                25th        Arrived in Malta for service with Mediterranean Fleet.

                                Prepared for support of allied landings in South France (Operation DRAGOON).

                                (Note: This Operation was under US overall command.)


August                  Joined HM Cruisers ROYALIST and DELHI with HM Escort Carriers ATTACKER

                                KHEDIVE, SEARCHER and PURSUER and nominated for duty in Task Group 88.1.

                                Carried out joint exercises in western Mediterranean prior to landings.

                15th        Embarked aircraft carried out patrols over beachhead and made offensive strike

                                in support of landings as required by Air Task Force Commander.

                                42 Sorties made.

                16th        40 Sorties made for support of landings.

                17th        Embarked aircraft took part with those from HMS KHEDIVE in attacks on Port Cros.

                                30 Sorties made including attacks on road and rail traffic.

                                One HELLCAT ditched.

                18th        16 Sorties flown

                19th        Embarked aircraft carried cut attacks on retreating German columns for a 48 hour period.

                                34 Sorties flown

                                See LANDINGS IN SOUTH OF FRANCE (HMSO).

                20th        Replenished at Maddalena

                21st         Embarked aircraft carried out attacks on targets in Rhone valley

                                (Note: Increased HELLCAT radius of operation proved of significant value.

                                36 Sorties flown.)

                22nd       Embarked aircraft flew 24 sorties against shore targets

                                Four HELLCAT Aircraft failed to return safely.

                23rd        Embarked aircraft made 32 sorties against shore targets.

                24th        Took passage to Maddalena with ships of Task Group 88.1 to refuel and re-arm.

                                (Note: Summary: 252 Sorties flown with loss of 11 aircraft.)

                27th        Released from DRAGOON and resumed RN control by CinC Mediterranean Fleet.

                                Nominated for service in British Aegean Force for support of allied re-occupation of islands

                                in eastern Mediterranean.

                                Passage to Alexandria with call at Malta.


September             Joined British Aegean Force with HMS HUNTER, STALKER, ATTACKER, SEARCHER,

                                PURSUER and KHEDIVE.

                                (Note: Other ships in Force included HM Cruisers ORION, AJAX, ROYALIST, AURORA,

                                ARGONAUT, BLACK PRINCE and COLOMBO, Destroyers of 24th Flotilla and

                                HUNT Class Destroyers. See Naval Staff History and Military Staff History.)

                2nd         Arrived at Alexandria.

                14th        Sailed from Alexandria with HMS PURSUER to provide air cover during operations against

                                evacuation craft and carry out air attacks on shipping and shore targets.

                                (Operation OUTING 1.)

                16th        Air Attacks made near Milos

                17th        Carried out anti-shipping sweeps and reconnaissance flights

                18th        Air attacks carried out on transport in Crete.

                19th        Air attacks carried out on Rhodes.                  

                21st         Replenished at Alexandria.

                30th        Deployed for air attacks in Aegean (Operation OUTING 2)



                1st           Carried out air operations in Aegean including shipping attacks and shore attacks in Crete.

                to            (Note: HELLCAT aircraft diverted to Turkey when undercarriage inoperable.)

                4th          Returned to Alexandria on release.

                8th          Sailed from Alexandria with HM Cruiser ROYALIST for further operations in Aegean.

                11th        Carried out attacks on shipping off Salonika prior to the allied re-occupation of Greece.

                12th        During return passage to Alexandria to refuel carried cut further air attacks on Rhodes

                13th        Sailed from Alexandria as part of Force 120 for allied occupation of Athens

.                               (Operation MANNA)

                                (For details see Military Staff History, Eastern Mediterranean).

                                (Note: Force 120 included HM Cruisers ROYALIST, ORION, AJAX, AURORA, BLACK

                                PRINCE, SIRIUS and COLOMBO, HM AA Ship ULSTER QUEEN, HMS STALKER

                                and HMS ATTACKER screened by HM Destroyers TROUBRIDGE,

                                TERMAGANT, TUSCAN, TYRIAN and Polish ORP GARLAND.)

                14th        Deployed for air operations on passage to Athens.

                15th        Provided air cover during re-occupation.

                19th        Embarked German Prisoners-of-War at Khios

                                Carried out dive-bombing attack on radar on Milos destroying this target,

                26th        Deployed in support of operations prior to re-occupation of. Milos (Operation CONTEMPT.)

                                (Note: The support included bombardment spotting and air strikes.)


November              Deployment in support of operations to re-occupy Aegean islands in continuation.

                                Nominated for return to UK for refit prior to service with East Indies Fleet

.                               (Note: East Indies Fleet was formed on 22nd November when some ships of Eastern Fleet

                                transferred to newly formed British Pacific Fleet.)

                14th        Provided cover for spotting aircraft during bombardment of Milos by HM Battleship

                                KING GEORGE V.

                15th        Passage to Gibraltar escorted by Polish destroyer ORP GARLAND.


December              Arrived at Newport, Mon. after landing 800 Squadron aircraft and personnel.

                                Taken in hand for refit and prepared for foreign service.


1 9 4 5


January                  On completion of post refit trials and work-up resumed operational service.

                                Embarked 800 Squadron aircraft and personnel before leaving UK.


February                Passage to Trincomalee via Mediterranean to join 21st Aircraft Carrier Sqdn.



                25th        Arrived at Colombo

                                Joined HM Escort Carriers BEGUM, EMPRESS, SHAH, AMEER, KHEDIVE, SLINGER

                                and SPEAKER in Eastern Fleet based at Trincomalee.


April                       Eastern Fleet deployment with Squadron.

                                Nominated for carrying out photographic reconnaissance flights at ports in southern Malaya

                                as part of Operation SUNFISH by East Indies Fleet

                                HELLCAT and AVENGER aircraft embarked to supplement 800 Squadron strength.

                8th          Sailed from Trincomalee as part of Force 63 for joint operation to carry out the

                                reconnaissance flights and a bombardments in the Andamans and Sumatra.

                                (Note: Bombardment group comprised RN battleship HMS QUEEN ELIZABETH and

                                French battleship RICHELIEU and HM Cruiser LONDON screened by HM

                                Destroyers SAUMAREZ, VERULAM and VIGILANT.)

                                Carrier group comprised HM Escort Carriers EMPEROR and KHEDIVE with HM

                                Cruiser CUMBERLAND screened by HM Destroyers VENUS and VIRAGO.)

                11th        Bombardment group detached for attacks on Sabang by battleships and cruiser with

                                air cover from the two CVE. During retaliatory air attacks two of enemy aircraft

                                shot down by fighters from CVE.

                12th        Planned launch of aircraft delayed by defect in catapult.

                                Ships refuelled from Tankers of Force 70.

                14th        Aircraft launched for reconnaissance over Penang, Port Swettenham and Port Dickson

                to            during which one enemy aircraft was shot down and one carrier aircraft lost.

                15th        Mission was successful.

                16th        Took part in air strikes at Emmahaven, port of Padang, Sumatra.

                                One submarine chaser (Ch 7) was sunk and a freighter damaged.

                20th        Returned to Trincomalee with Force 63.

                                Additional HELLCAT and AVENGER supplementary aircraft landed

                                For details see Naval Staff History and WAR WITH JAPAN (HMSO).

                23rd        Sailed with Eastern Fleet ships from Trincomalee to Akyab prior to provision of

                                air cover for assault convoys on passage to Rangoon (Operation DRACULA).

                27th        Deployed with HM Escort Carriers HUNTER, STALKER and KHEDIVE of Squadron

                to            covered by HM Cruisers PHOEBE and ROYALIST. Provided air cover during passage

                30th        of assault convoys.



                1st           Present during landings at Rangoon and provided air cover.

                4th          Released from DRACULA and took passage with ships of Squadron Sqdn. to carry out

                                air strikes on Burmese coastal targets between Mergui and Port Victoria.

                5th          Carried out air attacks with ships of Squadron till 6th May.

                7th          Passage to Trincomalee with Squadron.

                9th          Arrived at Trincomalee.

                10th        Joined Force 61 which was formed after report of Japanese warships on passage to


                                (Note: Force 61 comprised HM Battleship QUEEN ELIZABETH, French RICHELIEU, HM

                                Cruisers ROYALIST and CUMBERLAND, Dutch cruiser TROMP, HM Escort Carriers

                                HUNTER, KHEDIVE, SHAH and EMPEROR of 21st Carrier Squadron screened by

                                HM Destroyers SAUMAREZ, VENUS, VERULAM, VIRAGO, VIGILANT of 26th

                                Destroyer Flotilla and ROTHERHAM, TARTAR and NUBIAN of 11th Destroyer


                                Sailed from Trincomalee with Force 61 to intercept Japanese ships.

                                (Operation DUKEDOM).

                13th        Force 61 refuelled from Force 70 Replenishment Group.

                14th        Detached from Force 61 with ships of Squadron to position 50 miles west of Six

                                Degree Channel to carry out air search operations.

                15th        Aircraft from HMS SHAH operated from ship because of defective catapult in HMS SHAH.

                                Four AVENGER aircraft launched for to carry out search for Japanese ships.

                                Auxiliary Supply Ship KUROSHIO MARU and Submarine Chaser No 57 sighted.

                                Bomb attack made by one AVENGER aircraft which was hit by return fire and forced

                                into the sea.

                                (Note: Owing to a series of errors the crew were not located and their dinghy

                                drifted ashore when the aircrew were captured.

                                See WAR WITH JAPAN, SINK THE HAGURO and Naval Staff History.)

                                Further search for these two ships was unsuccessful and they escaped to Penang.

                                Later that morning an AVENGER aircraft belonging to HMS SHAH but operating from

                                ship sighted Japanese cruiser HAGURO and Japanese destroyer KAMIKAZE which were

                                bombed during the afternoon by 3 embarked AVENGER aircraft. Only slight damage was

                                (Note: This sighting resulted in a brilliant night torpedo action by ships of

                                the 26th Destroyer Flotilla during which HAGURO was sunk

                                See SINK THE HAGURO by J Winton and Naval Staff History.)

                21st         Returned to Trincomalee with Fleet units.


June                        Eastern Fleet deployment with Squadron in continuation.


July                         Deployed with HMS AMEER as part of Force 61 to provide cover for a minesweeping

                                operation off Car Nicobar by 6th Minesweeping Flotilla and launch air strikes

                                on airfields in North Sumatra (Operation COLLIE).

                                (Note: HM Cruiser NIGERIA was also part of Force 61 with HM Destroyers ROEBUCK

                                ESKIMO and VIGILANT as screen.)

                                WALRUS aircraft of 1700 Squadron and personnel joined.

                5th          Embarked aircraft carried cut air strikes during bombardments by HMS NIGERIA

                to            and attached destroyers. Six aircraft were lost.


                11th        Embarked aircraft launched for air strikes with HMS AMEER on airfields at Kota

                                Raja and Lho Nga in NW Sumatra.

                                Single Japanese aircraft which approached shot down.

                14th        Returned to Trincomalee with ships of Force 61.


August                  Prepared for cover of British landings in Malaya (Operation ZIPPER)

                15th        Sailed with East Indies Fleet to implement planned landings.

                                (Note: Fleet commanded by Admiral, 3rd Battle Squadron, in HMS NELSON.)

                                Setting up of advanced base at Penang (Operation JURIST.)

                16th        JURIST delayed for 48 hours By General Macarthur.

                                (See Final Report by SEAC (HMSO).

                19th        Further delay imposed until Japanese signed Surrender terms in Tokyo.

                28th        Arrived off Penang.

                                (Note: Pennant Number R307 was allocated for visual signalling purposes to

                                conform with US Navy identity for warships of this type.)


 September            Passage to landing area from Penang.


                9th          Provided air cover during landings with ships of Squadron

                                (Note: Squadron ships engaged included HM Cruiser ROYALIST, HM Escort Carriers

                                HUNTER, KHEDIVE, PURSUER, TRUMPETER and STALKER. HM Battleship

                                NELSON and French Battleship RICHELIEU with HM Cruisers CEYLON,

                                CLEOPATRA and NIGERIA also took part. For details of all ships in East Indies

                                Fleet on VJ Day see THE FORGOTTEN FLEET by J Winton and above references.

                10th        Deployed at Singapore with ships of Squadron.


P o s t   W a r   N o t e s


HMS EMPEROR remained in East Indies Fleet until 30th October 1945 when she took passage to UK via Colombo and Bombay. After arrival in Clyde on 4th December the ship Paid-off and was de-stored.. British equipment was removed in Plymouth during January 1946 and ship sailed for USA with a Steaming Party on 23rd of that month. She was returned to the US Navy at Norfolk, Va on 12th February and  sold for breaking up by an American ship breaker on 15th May1946.  







by Don Kindell


These convoy lists have not been cross-checked with the text above






Date convoy sailed

Joined convoy as escort

Convoy No.

Left convoy

Date convoy arrived








SL 158MK








(Note on Convoys)



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revised 15/10/10
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