maintenance on 16 June. The installation of a new heavy foremast and other work lasted until 21 July. On 10 September, König again went into the Baltic for training maneuvers. Operation Albion In early September 1917, following the German conquest of the Russian port of Riga, the German navy decided to eliminate the Russian naval forces that still held the Gulf of Riga. The (the Navy High Command) planned an operation to seize the Baltic island of , and specifically the Russian gun batteries on the Sworbe Peninsula. On 18 September, the order was issued for a joint operation with the army to capture and Moon Islands; the primary naval component was to comprise the flagship, Moltke, along with III Battle Squadron of the High Seas Fleet. V Division included the four König-class ships, and was by this time augmented with the new battleship Bayern. VI Division consisted of the five Kaiser-class battleships. Along with 9 light cruisers, 3 torpedo boat flotillas, and dozens of mine warfare ships, the entire force numbered some 300 ships, supported by over 100 aircraft and 6 zeppelins. The invasion force amounted to approximately 24,600 officers and enlisted men. Opposing the Germans were the old Russian pre-dreadnoughts and , the armored cruisers , , and , 26 destroyers, and several torpedo boats and gunboats. The garrison on numbered some 14,000 men. König departed Kiel on 23 September for Putziger Wiek, where the ship remained until 10 October. The operation began on 12 October; at 03:00 König anchored off in Tagga Bay and disembarked soldiers. By 05:50, König opened fire on Russian coastal artillery emplacements, joined by Moltke, Bayern, and the other three König-class ships. Simultaneously, the Kaiser-class ships engaged the batteries on the Sworbe peninsula; the objective was to secure the channel between Moon and Dagö islands, which would block the only escape route of the Russian ships in the Gulf. Both Grosser Kurfürst and Bayern struck mines while maneuvering into their bombardment positions, with minimal damage to the former. Bayern was severely wounded, and had to be withdrawn to Kiel for repairs. At 17:30, König departed the area to refuel; she returned to the Irben Strait on 15 October. On 16 October, it was decided to detach a portion of the invasion flotilla to clear the Russian naval forces in Moon Sound; these included the two Russian pre-dreadnoughts. To this end, König and Kronprinz,