Editing Indian Ocean raid (section)

{{redirect|Operation C|the 1991 video game|Operation C (video game)}}
{{for|the later Japanese raid|Indian Ocean raid (1944)}}
{{short description|1942 raid of Allied shipping by the Imperial Japanese Navy}}
{{Use dmy dates|date=June 2020}}
{{Use British English|date=September 2015}}
{{Infobox military conflict
| conflict          = Indian Ocean raid
| partof            = the [[Pacific War|Pacific Theatre]] of [[World War II]]
| image             = Dorsetshire&Cornwall.jpg
| image_upright        = 1.23
| caption           = British [[heavy cruiser]]s {{HMS|Dorsetshire|40|6}} and {{HMS|Cornwall|56|2}} under Japanese air attack and heavily damaged on 5 April 1942.
| date              = 31 March – 10 April 1942
| place             = [[Indian Ocean]] and [[British Ceylon]]
| result            = Japanese victory
| combatant1        = {{flag|United Kingdom}}
* {{flag|British Ceylon}}
{{flag|Australia}}<br />{{flagdeco|Netherlands}} [[Dutch government-in-exile|Netherlands]]<br>{{flag|United States|1912}}<br>{{flag |Canada|1921}}
| combatant2        = {{flagicon|Empire of Japan}} [[Empire of Japan|Japan]]
| commander1        = [[James Somerville (admiral)|James Somerville]]
| commander2        = [[Chūichi Nagumo]]<ref name="Boyd_373"/><br />[[Mitsuo Fuchida]]
| units1            = {{flagicon|United Kingdom|naval}} [[Eastern Fleet]]
| units2            = {{flagicon|Empire of Japan|naval}} [[Kido Butai|Combined Fleet]]
| strength1         = 2 [[aircraft carrier|carriers]]<br />1 [[light aircraft carrier|light carrier]]<br />5 [[battleship]]s<br />7 [[cruiser]]s<br />15 [[destroyer]]s<br />7 [[submarine]]s<br />100+ [[Military aircraft|aircraft]]<br /> 30 smaller warships<br />50+ [[merchant ship]]s.
| strength2         = 5 carriers<br />1 light carrier<br />4 battleships<br />11 cruisers<br />23 destroyers<br />5 submarines<br /> 275 aircraft
| casualties1       = 1 light carrier sunk<br />2 [[heavy cruiser]]s sunk<br />2 destroyers sunk<br />1 [[Armed Merchant Cruiser]] (AMC) sunk<br />1 [[corvette]] sunk<br />1 [[Sloop-of-war|sloop]] sunk<br />20 merchant ships sunk<br />54 aircraft destroyed<br />825 killed
| casualties2       = 18 aircraft destroyed<br />31 aircraft damaged<br />32 killed
| campaignbox       =
}}
{{Campaignbox Pacific 1941}}
{{Campaignbox South-East Asia}}
{{Campaignbox Indian Ocean Theatre}}
{{Campaignbox South-East Asian Theatre}}

The '''Indian Ocean raid''', also known as '''Operation C'''<ref name="Boyd_364"/> or '''Battle of Ceylon''' in Japanese, was a naval sortie carried out by the [[Imperial Japanese Navy]] (IJN) from 31 March to 10 April 1942. Japanese aircraft carriers under Admiral [[Chūichi Nagumo]] struck Allied shipping and naval bases around [[British Ceylon]], but failed to locate and destroy the bulk of the British [[Eastern Fleet]]. The Eastern Fleet, commanded by Admiral Sir [[James Somerville (admiral)|James Somerville]], was forewarned by intelligence and sailed from its bases prior to the raid; its attempt to attack the Japanese was frustrated by poor tactical intelligence.

Following the attack, the British expected a major Japanese offensive in the [[Indian Ocean]]. The main base of the Eastern Fleet relocated to [[East Africa]], and Ceylon was reinforced, but Somerville kept his fast carrier division, ''Force A'', "...in [[Indian Ocean|Indian waters]], to be ready to deal with any attempt by the enemy to command those waters with light forces only."<ref name="Roskill_29">Roskill, p. 29</ref> However, the Japanese had no short-term plans to follow up on their success, and within the year operations in the Pacific made it impossible to do so.