According to the Introduction to the History and Antiquities of Essex Vol. 1 page v (which was written by G H Martin) in the reproduction issue of 1978:
"Philip Morant was born in Saint Saviour's parish, Jersey on 6 October 1700. He was the second son and third child of Stephen Mourant (sic) and Mary Filleul; the family had in the past enjoyed a comfortable property, and showed a pedigree rising to the late fifteenth century. Philip, who spelt his name Mourant until he was in his thirties, spoke and wrote French in his childhood. He was sent to school in England, however, at Abingdon and stayed there from about 1712 until he was seventeen. On 16 Dec 1717 he went to Oxford [Pembroke College] and graduated in 1721. The next year he was ordained at Saint Martin-in-the-Fields* by the bishop of Norwich acting for the bishop of London. Some of his biographers have said that in this year he was offered the chaplaincy of the English church in Amsterdam, which he certainly acquired in 1732, but it seems likely that the dates have been confused....On 26 Sep 1722, three days after he was ordained, Philip Morant 'came to Mr Tindal [Rector of Great Waltham] by the Chelmsford coach' "
He seems to have been a clergyman in Essex until his wife died in 1767. He then lived with his married daughter (married name Astle) at Battersea until his death in 1770. His last years were spent writing a history of Parliament.
* I assume that this is the huge church next to Trafalgar Square in London.