Thomas Berry was born in 1737 or 1738, the eldest son of John Berry (1702-1768) who was buried at Kilbeggan. In 1759 he married Frances Berry. Through her connection, he acquired Eglish Castle in the 1770. He was reputed to hold a large tract of land in the Barony of Philipstown as well as land in the Barony of Eglish. He farmed much of the land himself which for the most part was grazed by sheep. He also established a bleach green at Eglish. He died in 1815 at Eglish and was buried there.
In 1759 Thomas Berry married Frances. They lived at Eglish Castle and had sixteen children.