Bagot was born in Nurney in County Kildare, Ireland, son of Christopher Bagot and Elizabeth, "née" Clibborn. He joined the British Army in 1805 and was gazetted to the 87th Foot Regiment. He is reported as having served with distinction in India during the Mahratta War and was promoted to the rank of captain. About the year 1819 he was retired on half pay to Ennis in County Clare, where he was appointed to the Commission of the Peace, and generally lived the life of a country gentleman.