Per L&M Companion:
A financial expert, and a colleague of Ashley (Shaftesbury)
( http://www.pepysdiary.com/encyclopedia/215/ ) at the Prize Office, where he was a Commissioner, 1665 - 7. (He had a similar post in 1656.) After service in the parliamentary army he had done well out of speculation in confiscated Irish land, and had also gathered to himself several lucrative posts -- in 1659 as auditor for the army accounts, in 1666 as Comptroller of the Excise and in 1669 as farmer of the Irish revenue.
5 Dec 2018, 5:46 p.m. - San Diego Sarah
Phil kindly checked the correct spelling of this man's name for me.
L&M say Kingdon -- with two Ns -- not an M at the end.
Chart showing the number of references in each month of the diary’s entries.