Hi Spes Ultra
According to the Clergy of the Church of England database (db.theclergydatabase.org.uk), David Nairn was ordained deacon on 15 Apr 1622 at Canterbury, with a qualification of MA. Assuming he has been 4-5 years at University for the MA and entered University at age 16 to 18, then he would have been born about 1600-02. I have not found him in the published records of Oxford or Cambridge universities, so he may have attended a Scottish university.
He was curate at Swingfield 1626-65, and curate at Paddlesworth 1630-65.
He married Mary Chapman on 25 Apr 1627 at Acrise. She may be buried as Mrs Nairn on 21 Aug 1663 at Wingham.
I believe their children were:
George, yeoman of Wingham, baptised 21 Feb 1627/28 at Elham; mentions his brothers Richard David and William in his will made in 1676; also mentions several cousins and nephews named Fagg - presumably on his mother's side of the family (no luck yet in tracing the connection);
Richard, miller of Wingham, bapt 1 Feb 1629/30 at Swingfield;
Agnes, bapt 8 Mar 1631/32 at Swingfield;
David, bapt 28 Aug 1634 at Swingfield "son of David Nairne and Mary Chapman";
William, brewer of Wingham, bapt 21 Dec 1737 at Swingfield;
Mary, married 10 Dec 1662 at Paddlesworth, buried 1 Mar 1694 at Paddlesworth;
Joannah, buried 14 Nov 1663 Swingfield.
As curate of Swingfield and Paddlesworth he is bondsman for four marriages 1634-42, testifying to the consent of the bride's father in one.
All these records from the Bishops Transcripts which have a gap 1642 to 1662, in which I presume the births of Mary and Joannah occurred. My chart has for years had another daughter Ellen died in 1661 at Swingfield, but I cant now find my notes for this event, but if true her birth probably also occurred in the gap. I dont know if the original registers have any events recorded in the gap. They have now been filmed, but are not readily accessible through familysearch.
There is another Nairn clergyman in Kent at this time who did come from Scotland - Rev. James Nairne vicar of the Isle of Grain from 1669 to his death there in 1677. His will leaves legacies to his mother Dorothy, citizen of St Andrews, his brother Alexander, also of St Andrews, his aunt Frances [Vigion] of London, and kinswoman Thomasin Tredwin, also of London. I think James may have been born 1642 at St Andrews to James Nairne and Dorothy Quarles. His MA is recorded at Oxford in 1668 "incorp. St Andrews". I presume this means he started university at St Andrews and either transferred, or completed his BA at St Andrews and then did his MA at Oxford. He died relatively young and does not appear to have married or had children. I can find no connection to the other Nairns in Kent. The same Christian names recur again and again in the (presumed) descendants of Rev. David Nairn, but not one Alexander as a far as I know.
I did not know about the 1629 marriage for a Richard Nearne at Eastbourne. Do you have a reference?
As to how the Nairns ended up in Kent, I presume some Scots saw opportunities in the accession of James VI to the throne of England in 1603. It would help to know who had the patronage of the livings at Swingfield and Paddlesworth. British History Online suggests for Swingfield - maybe Sir T. Palmer, bart.; and Paddlesworth was a chapelry of Snodland which was under the patronage of the Bishop of Rochester with possible connections to the Palmer family.