In 1644, he joined Sir Robert Pye's cavalry regiment, fighting at Lostwithiel and the Second Battle of Newbury, before transferring to the New Model Army in 1645 as a major in Colonel Richard Graves' regiment. Although the regiment was part of the force sent to relieve Taunton and missed the Battle of Naseby, he took part in the South-Western campaign, where it fought at Langport and Bristol.