Which king was on the throne in 1915?

In 1915, King George V was on the throne in the United Kingdom. He reigned from 1910 until his death in 1936, and his reign included significant events such as World War I. George V was the first British monarch of the House of Windsor, which he established in 1917, changing the royal family's name from the House of Saxe-Coburg and Gotha due to anti-German sentiment during the war.