Complex sentence: William supported women's suffrage and the Boer cause in the Boer War, and was a firm supporter of Temperance and, until he allied himself with the Conservatives, David Lloyd-George.
Split into simpler sentences: William supported women's suffrage and the Boer cause in the Boer War. He was a firm supporter of the temperance movement and, until he allied himself with the Conservatives, David Lloyd-George.