First Happy Time

{{short description|Period of naval battles of the Second World War}}

{{Campaignbox Atlantic Campaign}}

Image:Torpedoed merchant ship.jpg

The early phase of the Battle of the Atlantic during which German Navy U-boats enjoyed significant success against the British Royal Navy and its Allies was referred to by U-boat crews as "the Happy Time" ("Die Glückliche Zeit"),{{cite web|last=Purnell |first=Tom |title=The "Happy Time" |work="Canonesa", Convoy HX72 & U-100 |date=April 11, 2003 |url=http://homepage.ntlworld.com/annemariepurnell/can3.html |access-date=September 1, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20071001045906/http://homepage.ntlworld.com/annemariepurnell/can3.html |archive-date=October 1, 2007 |df=mdy }} and later the First Happy Time, after a second successful period was encountered.

It started in July 1940, almost immediately after the Fall of France, which brought the German U-boat fleet closer to the British shipping lanes in the Atlantic. From July 1940 to the end of October, 282 Allied ships were sunk off the north-west approaches to Ireland for a loss of 1,489,795 tons of merchant shipping.Blouet, Brian W. Global Geostrategy: Mackinder and the Defence of the West, p. 131

The reason for this successful Axis period was the British lack of radar and huff-duff-equipped ships which meant that the U-boats were very hard to detect when they made nighttime surface attacks – ASDIC (sonar) could only detect submerged U-boats.

When it ended is a matter of interpretation, with some sources claiming October 1940Hughes, Terry; Costello, John. The Battle of the Atlantic, p. 88 and others extending it to April 1941,Macintyre, Donald G. F. W. The Naval War Against Hitler, p. 52 after the Germans lost three prominent U-boat commanders: Günther Prien, Joachim Schepke, and Otto Kretschmer.{{cite web |url=https://www.usni.org/magazines/navalhistory/2008-06/battle-had-be-won |title=The Battle That Had to Be Won |access-date=2017-03-09 |last=Milner |first=Marc |date= June 2008|work=Naval History Magazine |publisher=United States Naval Institute}}