The Battle of Cocos was a single-ship action that occurred on 9 November 1914, after the Australian light cruiser HMAS Sydney responded to an attack on a communications station at Direction Island by the German light cruiser SMS Emden.
During a two-month period, the German cruiser captured or sank 25 civilian vessels, shelled Madras, and destroyed two Allied warships at Penang. In early November, Emden ’s commanding officer, Karl von Müller, decided to attack the communications station at Direction Island, in the Cocos (Keeling) Islands, to hamper Allied communications and frustrate the search for his ship. Around the same time, the first convoy of Australian and New Zealand soldiers bound for Europe sailed from Albany, Western Australia, with Sydney, under the command of John Glossop, and three other warships escorting.
During the night of 8–9 November, Emden reached the islands, and sent a shore party to disable the wireless and cable transmission station on Direction Island. The station was able to transmit a distress call before it was shut down; this was received by the nearby convoy, and Sydney was ordered to investigate. Emden opened fire at 09:40, surprising those aboard Sydney by scoring hits well beyond what British intelligence estimated her guns were capable of. The German ship was unable to inflict disabling damage to the Australian cruiser before Sydney opened up with her more powerful main guns. At 11:20, von Müller ordered that Emden beach on North Keeling Island. The Australian warship broke to pursue the collier Buresk, which scuttled herself, then returned to North Keeling Island at 16:00. At this point, Emden ’s battle ensign was still flying, and after no response to instructions to lower the ensign, Glossop ordered two salvoes shot into the beached cruiser. Sydney had orders to ascertain the status of the transmission station, but returned the next day to provide medical assistance to the Germans.
Of Emden ’s crew, 134 were killed and 69 wounded, compared to only 4 killed and 16 wounded aboard Sydney. The German survivors were taken aboard the Australian cruiser, with most transferred to auxiliary cruiser Empress of Russia on 12 November. Sydney rejoined the ANZAC convoy in Colombo, then spent the rest of the war assigned to the North America and West Indies Station, then the British Grand Fleet. von Müller and some of his officers were imprisoned in Malta, and the rest of the German personnel were sent to prisoner-of-war camps in Australia. An additional 50 German personnel from the shore party, unable to be recovered before Sydney arrived, commandeered a schooner and escaped from Direction Island, eventually arriving in Constantinople. The defeat of the last German ship in the region allowed RAN warships to be deployed to other theatres, and troopships were able to sail unescorted between Australia and the Middle East until renewed raider activity in 1917.