'J' (i) was a British naval undertaking to rescue and bring to England a party comprising Queen Wilhelmina, other members of the Dutch royal family, and senior members of the Dutch government and armed forces, in the destroyer Hereward (13 May 1940).

Queen Wilhelmina had wished to remain in the Netherlands after the 'Gelb' invasion of her country, and had planned to move to the southern province of Zeeland to remain with her forces and co-ordinate further resistance to the Germans from Breskens. After leaving Den Haag, the Dutch queen boarded Hereward for the journey south, but only then learned that Zeeland had come under heavy air attack, and found herself with no option but to accept King George VI’s offer of refuge in the UK, where she headed the Dutch government-in-exile.

During the evening of the same day the destroyers Codrington, Hyperion and Windsor arrived in IJmuiden to evacuate Crown Princess Juliana and other senior members of the Dutch government to Harwich.