He was educated at Colchester Royal Grammar School from 1702, before possibly spending some time at Cambridge University and entering Gray's Inn to become a lawyer in 1724.

"[4] Locally, Gray is now most remembered for being given Colchester Castle as part of his marriage settlement, and subsequently making a number of efforts to preserve it for future generations.

Likewise, he also purchased a great part of the surrounding land, which was, a hundred and fifty years later, given to the town to become Castle Park.

He was also responsible for management of a house, also part of his marriage settlement, which now forms Hollytrees museum, named after holly trees that Gray planted during his ownership of the building.

[5] The bulk of his estate was left to his friend James Round of Little Birch and his wife, Tamar, who was the daughter and heir of Gray's stepson, Peter Creffeild.