Stibber arrived in India in 1756 and took part in the Battle of Plassey in 1757.[2] He then raised a battalion of native infantry at Bankipore in 1761 and commanded them at the Siege of Patna where he was wounded in 1763.[2] He commanded the left wing of the Army at the Battle of Buxar in 1764 and captured Chunar in 1765.[2]
He was twice Commander-in-Chief, India, firstly from 1777 to 1779 and then again from 1783, following the death of Sir Eyre Coote, to 1785.[3] He made a huge wealth during his service in India, when in England he resided at Hereford Street with his 3 children and wife. Stibbert then commissioned John Crunden the architect of Hereford Street to build his country estate the first Portswood House at Portswood in Hampshire in 1778.[4][5][6]
His grandson, Frederick Stibbert, used the family's wealth to establish the Stibbert museum in Florence.[7] He made the family home on the Hill of Montughi, which was originally purchased by his mother, into a museum to hold his collection.[8]