A panoramic view of Lushunkou (a district in the municipality of Dalian, Liaoning province, also called Lushun City or Lushun Port, formerly known as both Port Arthur and Ryojun). During the Russo-Japanese war, the Russians surrendered Port Arthur to the Japanese after nearly a year's siege: the Japanese expended 58,000 killed or wounded to obtain the town. As can be seen here, Lushunkou boasts an excellent natural harbour, the possession and control of which became a 'casus belli' (justification for the act of war) during the Russo-Japanese War (1904?1905).