Complex sentence: He stood for the Progressive Party, a London group active in the 1890s, and was later in 1907 elected to the London County Council; in the same year he published "The Socialist's Church".
Split into simpler sentences: He stood for the Progressive Party, a London group active in the 1890s, and was later, in 1907, elected to the London County Council. In the same year he published "The Socialist's Church".