Siege of Port Arthur ended

The Siege of Port Arthur (Japanese:旅順攻囲戦, Ryojun Kōisen; Russian:Оборона Порт-Артура, Oborona Port-Artura, August 1, 1904 – January 2, 1905), the deep-water port and Russian naval base at the tip of the Liaotung Peninsula in Manchuria, was the longest and most violent land battle of the Russo-Japanese War.

Port Arthur was widely regarded as one of the most strongly fortified positions in the world at the time. However, during the First Sino-Japanese War, General Nogi Maresuke had taken the city from the forces of Qing China in only a few days. The ease of his victory during that previous conflict, and overconfidence by the Japanese General Staff in Japan's ability to overcome improved fortifications made by the Russians, led to a much longer campaign, with much heavier losses than expected.

The capture of Port Arthur and the subsequent Japanese victories at the Battle of Mukden andTsushima gave Japan a dominant military position, resulting in favorable arbitration by U.S. President Theodore Roosevelt in the Treaty of Portsmouth, which ended the war.

The loss of the war in 1905 led to major political unrest in Imperial Russia (see:Russian revolution of 1905).