acquired several light cruisers, destroyers and submarines. Just before World War II the navy planned to acquire several battlecruisers but like the dreadnoughts these were never built due to the war. World War II and decolonisation During the Second World War the Dutch navy was based in Allied countries, due to the conquest in May 1940 of the Netherlands by Nazi Germany. The Dutch navy had its headquarters in London and smaller offices in Sri Lanka and Australia. At the start of the Second World War on 10 May 1940 the Royal Netherlands Navy had three operational submarines in the Netherlands, namely HNLMS O 9, O 10 and O 13. O 11 was being repaired, while O 8 and O 12 were undergoing maintenance. Meanwhile, O 14 and O 15 were active at the time in the Caribbeans. Furthermore, seven submarines were in various stages of completion at different yards. On the other hand, the Dutch navy had 15 operational submarines in the Dutch East Indies. These submarines played an important role during the war, by confronting and sinking enemy ships. For example, HNLMS O 16 and K XVII sunk several Japanese ships in 1941. However, there were also losses in this theater, both HNLMS O 16 and K XVII were sunk in December 1941. Around the world Dutch naval units were responsible for troop transport, for example during Operation Dynamo in Dunkirk and D-Day, they escorted convoys and attacked enemy targets. During the war the navy suffered heavy losses, especially in defence of the Dutch East Indies against the Japanese in the Battle of the Java Sea (February 1942) in which rear admiral Karel Doorman went down with most of his ships and with 2,300 of his crew. The first women were employed as non-combatants in 1944, and took on combat functions in 1980. In 1946, the Netherlands had a total of seven operational submarines in service; HNLMS O 21, O 23, O 24, O 27, Dolfijn, Zwaardvisch and Tijgerhaai. Since the home port at Den Helder was in ruins, these submarines were for the time being using the Waalhaven in Rotterdam as base. After the war, the relations between the Netherlands and its colonies also changed dramatically. The establishment of the Republic of Indonesia two days after the Japanese surrender cooled the Dutch plans for re-establishing its colonial authority. It took four years of war before the Netherlands