She saw some limited duty in the Baltic Sea against the Russian Navy, including serving as part of a support force during the Battle of the Gulf of Riga in August 1915.

[6] The ship's secondary battery consisted of fourteen 15 cm (5.9 in) SK L/45 guns, all of which were mounted in casemates in the side of the upper deck.

[8] Ernst Günther II, Duke of Schleswig-Holstein, gave a speech at the launching ceremony, and his wife, Princess Dorothea, christened the ship Helgoland,[9] named for the offshore islands seen as vital to the defense of the Kiel Canal.

Her first commander was Kapitän zur See (KzS—Captain at Sea) Friedrich Gädeke, though the following month, he was replaced by KzS Gottfried von Dalwigk zu Lichtenfels.

Trials were concluded on 19 December, and the following day, she arrived in Wilhelmshaven, where she joined I Battle Squadron,[11] replacing the pre-dreadnought Hannover.

A routine voyage to Norwegian waters was cancelled that year due to political tensions in Europe, which remained high even after the conclusion of the Agadir crisis.

On 23 May 1913, Helgoland was present for the dedication of a memorial stone to German sailors who had died in the area in recent years, including men from the torpedo boats G171 and S178, the salvage ship Unterelbe, and the zeppelin L1.

[11][12] On 10 July 1914, Helgoland left the Jade Estuary to take part in the annual summer training cruise to Norway.

The fleet, along with several German U-boats, assembled at Skagen on 12 July to practice torpedo boat attacks, individual ship maneuvers, and searchlight techniques.

Despite her proximity to the battle, Helgoland was not sent to aid the beleaguered German cruisers, as she could not be risked in an unsupported attack against possibly superior British forces.

[28] Helgoland and the rest of the High Seas Fleet sortied to support the battlecruisers of I Scouting Group during their raid on Yarmouth on 2–3 November, though the battleships did not take direct part in the operation.

[31] On 17 January 1915, Ingenohl ordered Helgoland to go back to the docks for more maintenance, but she did not enter the drydock until three days later, owing to difficulties getting through the canal locks.

[33] On 10 February, Helgoland and the rest of I Squadron sailed out of Wilhelmshaven towards Cuxhaven, but heavy fog impeded movement for two days.

[9] Helgoland, her three sister ships, and the four Nassau-class battleships were assigned to the task force that was to cover the foray into the Gulf of Riga in August 1915.

The German flotilla, which was under the command of Hipper, also included the battlecruisers Von der Tann, Moltke, and Seydlitz, several light cruisers, 32 destroyers and 13 minesweepers.

The dreadnoughts Nassau and Posen were detached on 16 August to escort the minesweepers and to destroy Slava, though they failed to sink the old battleship.

Another battlecruiser operation, the bombardment of Yarmouth, took place on 24–25 April; once again, Helgoland and the rest of the High Seas Fleet cruised in support.

Nomad, which had been attacked by the Kaiser-class ships at the head of the line, exploded and sank at 18:30, followed five minutes later by the Nestor, sunk by main and secondary gunfire from Helgoland, Thüringen and several other German battleships.

The shooting stopped quickly though, as the Germans lost sight of their target; Helgoland had fired only about 20 shells from her main guns.

[47] At around midnight on 1 June, the Helgoland- and Nassau-class ships in the center of the German line came into contact with the British 4th Destroyer Flotilla.

[52] Following the return to German waters, Helgoland and Thüringen, along with the Nassau-class battleships Nassau, Posen, and Westfalen, took up defensive positions in the Jade roadstead for the night.

The raid resulted in the action of 19 August 1916, an inconclusive clash that left several ships on both sides damaged or sunk by submarines, but no direct fleet encounter.

The failure of the operation (coupled with the action of 19 August) convinced the German naval command to abandon its aggressive fleet strategy.

In October 1917 Helgoland, in company with Oldenburg, went to Amrum to receive the light cruisers Brummer and Bremse, which were returning from a raid on a British convoy to Norway.

On 27 November the ship traversed the Kaiser Wilhelm Canal into the Baltic, but did not participate in Operation Albion, the occupation of the islands in the Gulf of Riga.

There, she resumed local defensive operations; she spent the rest of the year and into 1918 with these activities, particularly guarding minesweepers keeping channels open in the North Sea.

[57] German attacks on shipping between Britain and Norway, which had begun in late 1917, prompted the Grand Fleet to begin escorting convoys with a detached battle squadron.

This decision presented the Germans with the opportunity for which they had been waiting the entire war: a portion of the numerically stronger Grand Fleet was separated and could be isolated and destroyed.

[63] The rebellion then spread ashore; on 3 November, an estimated 20,000 sailors, dock workers, and civilians fought a battle in Kiel in an attempt to secure the release of the jailed mutineers.

The following day, a sailors' council took control of the base, and a train carrying the mutineers from Helgoland and Thüringen was stopped in Cuxhaven, where the men escaped.