During the early part of World War I, the German cruiser Konigsberg was based in German East Africa and represented a serious threat to British shipping in the Indian Ocean. At the commencement of the war the light cruiser Konigsberg had left the harbour of Dar-es-Salaam and had, on the 29th September, surprised and destroyed the English cruiser Pegasus at Zanzibar. Then several large enemy cruisers had arrived and industriously looked for the Konigsberg. After successful cruises in the Indian Ocean the Konigsberg had concealed herself in the Rufiji River, but her whereabouts had become known to the enemy. The enemy bombarded the Konigsberg, which was at anchor in the river with aeroplane observation. The attack was beaten off, but when it was repeated on July, the Konigsberg suffered severely. The gun-detachments were put out of action. The severely wounded captain had the breech-blocks thrown overboard and the ship blown up.