In an attempt to lure out and destroy a portion of the Grand Fleet, the High Seas Fleet, composed of sixteen dreadnoughts, six predreadnoughts and supporting ships, departed the Jade Bight early on the morning of 31 May. The fleet sailed in concert with Hipper's five battlecruisers. Room 40 had intercepted and decrypted German radio traffic containing plans of the operation. In response the Admiralty ordered the Grand Fleet, totalling some 28 dreadnoughts and 9 battlecruisers, to sortie the night before to cut off and destroy the High Seas Fleet.