The Mark IV Tank was a British tank used during World War I, first introduced in 1917. It was designed to cross trenches and navigate rough terrain, featuring a rhomboid shape that allowed it to climb over obstacles. The tank was equipped with machine guns and had a crew of up to six men. The Mark IV came in two versions: "Male," armed with machine guns, and "Female," equipped with cannons. It played a significant role in the war, marking a shift in warfare by combining mobility and firepower. Its design influenced future tank development in the years to come.