David Quidnunc • Link
PROBABLY Charles, L&M say
It is "probably" Charles Boyle (or possibly his brother, Richard) who appears twice in the diary in April 1660 (and, if it is Charles, never again). Latham & Matthews edition of the diary tell us nothing about him personally, but they give us some details about his relations who figure in the diary, mostly after 1664:
FATHER -- RICHARD (d. 1643):
Charles was the second son of the 2nd earl of Cork. The Boyles were "one of the greatest Royalist families of Ireland."
BROTHER -- ROBERT BOYLE (1627-91):
Charles's brother and Richard's seventh son was a great scientist, one of the founders of the Royal Society.
BROTHER -- ROGER (1621-79):
Baron Broghill, earl of Orrery, a soldier, dramatist and politician.
BROTHER -- RICHARD "THE RICH" (1612-98):
This may be the Boyle mentioned in April 1660. His marriage enriched him. Lord Treasurer of Ireland (1660-95). One of his daughters marries one of the sons of Edward Mountagu, Pepys's patron.
-- L&M, Volume 10 (companion) and 11 (index)