 Complete the following phrase:  Schleswig-Holstein then participated in a fleet advance to the Dogger Bank on 2122 April 1915. On 1112 September II Reconnaissance Group conducted a minelaying operation off the Swarte Bank with II Squadron in support. This was followed by another sweep by the fleet on 2324 October that ended without result. II and III Battle Squadron dreadnoughts conducted an advance into the North Sea on 57 March 1916; Schleswig-Holstein and the rest of II Squadron remained in the German Bight, ready to sail in support. They then rejoined the fleet during the operation to 