Passage: The Battle of Mukden commenced on 20 February 1905. In the following days Japanese forces proceeded to assault the right and left flanks of Russian forces surrounding Mukden, along a 50-mile (80 km) front. Approximately half a million men were involved in the fighting. Both sides were well entrenched and were backed by hundreds of artillery pieces. After days of harsh fighting, added pressure from the flanks forced both ends of the Russian defensive line to curve backwards. Seeing they were about to be encircled, the Russians began a general retreat, fighting a series of fierce rearguard actions, which soon deteriorated in the confusion and collapse of Russian forces. On 10 March 1905, after three weeks of fighting, General Kuropatkin decided to withdraw to the north of Mukden. The Russians lost 90,000 men in the battle.

Question: What month did the Battle of Mukden begin?
February