Late in November 1916, the German commerce raider Wolf, laden with 100 tonnes of mines, set out on a journey of 100,000 kilometres across three oceans. After the ship reached home, in February 1918, 442 days later, its guns and mines had destroyed more than twenty Allied vessels. Hundreds of their crews and passengers had been held captive. When the voyage of the Wolf began, German U-boats were sinking hundreds of thousands of tonnes of shipping each month. The belated adoption of the convoy system drastically reduced those losses, so that the Germans, rather than the British, suffered the worse privation in the last year of the Great War. In that time, Wolf was the only German surface warship not penned up by the British naval blockade.