Long was appointed High Sheriff of Wiltshire in 1512, 1526, 1536 and 1542, and High Sheriff of Somerset and Dorset in 1538. He replaced Sir Edward Darrell when the latter died as Member of Parliament for Wiltshire in 1532, and was re-elected in 1552. He was also Hereditary Bailiff of Charlton Wood and Keeper of Braden Forest, east of Malmesbury. Together with his brother Richard, he was present at the baptism of Prince Edward. He inherited the manor of Stock & Stockley from his father and later purchased the manor of South Wraxall.
