Complex sentence: He served in the 1st Foot Guards for twenty-five years, became the deputy lieutenant of Leicestershire, and was the colonel of the Leicestershire Yeomanry when it was raised during the crisis of 1794.
Split into simpler sentences: He served in the 1st Foot Guards for twenty-five years, rising to the rank of lieutenant-colonel. He became the deputy lieutenant of Leicestershire, and was the colonel of the Leicestershire Yeomanry when it was raised during the crisis of 1794.