Fleetwood Dormer's inscription in the book he gave to the Cathedral Library indicates that he was a firmarius ('farmer', tenant or lessee) of Christ Church.
The Cathedral Archives have records of 1677 (Fleetwood Dormer of the Inner Temple) and 1684 (Sir Fleetwood Dormer of the Middle Temple) signing contracts with the Dean and Chapter. The Treasurer's Book for 1676/1677 records a fine for renewal of a lease: 'June 27 Rec. of Mr Dormour for Newington tenement — [£]60 0 0'.
He is probably the (Sir) Fleetwood Dormer recorded by Foster, Alumni Oxonienses, 1500–1714:
s. Fleetwood, of Lee Grange, Bucks, militis. Pembroke Coll., matric. 12 Dec., 1634, aged 18; B.A. 10 June, 1637, of Arle Court, co. Gloucester, baptized 21 May, 1616, entered the Middle Temple 1637, knighted at Whitehall 13 July, 1678, emigrated to Virginia, died at Cheltenham 27 Aug., 1696, aged 81. 
- Shelfmark W/C-4-8
- Sanctes Pagninus. Thesaurus linguae sanctae.
- Inscription on title page: Donum Dni Fleetwood Dormer Firmarij hujus Ecclesiæ
- Canterbury Cathedral Archives CCA-DCc-TB/13, p. 11
- Foster, Inns of Court Reg.
- Some Emigrants to Virginia, edited by William G. Stanard, 2nd ed. 1915, p. 31
- L. G. Tyler, Encyclopedia of Virginia Biography, 1915, vol. 1, p. 224