Sixth son of James Montague, esq. of Lackham, Wilts., and grandson of Henry, 1st Earl of Manchester. b at Lackham School, Knotting, Beds. (private). Christ’s College Cambridge. Adm. pens. (age 18) 15 April 1668. Matriculated Easter 1668. BA 1671/2. MA 1675. King’s College Cambridge MA Fellow of Christ’s College Cambridge. Incorporated At Oxford 13 July 1680. Deacon and Priest 4 July 1676 (Peterborough) Fellow of Eton. Rector of Burton Latimer 8 July 1676. Rector of Everdon, subsc. 21 June 1683, inducted 23 June 1683, resigned in a few months. Headmaster of Eton. Died 29 (?20) Jan buried 22 Jan 1718/19 at Burton Latimer aged 68. (M.I.) Admin of T. Mountague, Rector of Burton Latimer gr. 12 Feb 1718/19 to W. West of Laycock, Wilts, gent. the principal creditor. Inventory taken 9 Feb 1718/9 £234.2s.10d, including study and books £40.

(Reference “Northamptonshire and Rutland Clergy from 1500” (1938-43) by Henry Isham Longden)

Being Rector of Burton Latimer for 42 years, from the age of 24 to his death in 1719, gave Thomas Mountagu a clear insight into the lives of his parishioners which he used to full advantage when writing some of the entries in the Parish Registers. During his time there were several Non-conformist groups in and around Burton Latimer and he obviously did not approve of any of them.

In January 1710 he writes: "Robinson - child of Francis Robinson - called Henry - was buried with the burial of an ass". (See Jeremiah XXII v19)

In July 1712: "John Alderman a mungrill quaker, at the quakers burial place, where there was a funeral oration, or sermon made by one of their persuasion of three hours long."  

In March 1714: "Henry Robinson - An anabaptist preacher. He was desirous to be buried in the church, who all his life time never came to serve God in that orthodox manner as established by law and for that reason, was buried in the churchyard without having the burying service read at his grave."

He was not always so unkind, in November 1710 he writes: "Rebecca Wootton daughter of my tenant Wm: and Ann was a child of great hopes, but alas! Snatched away before she was 5 years of age."

His comments are usually about people who have been buried but there are others, as at the marriage of John York and Abigail Hunt in March 1712, when he writes: "They are like to be very happy in each other in procreation of children, for the good woman has as ‘tis said, gone above half her time, the truth of which will be manifest if she be brought to bed much before the time that’s usually allowed in such cases." Their daughter Susanna was baptised 2 May 1712.