I can confirm the Catherine/Katherine Pegge story. Charles Fitzcharles did die at the Siege of Tangiers of nothing more glorious than a cold having spent the night in an old fort. I believe he was the commander of the 2nd Regiment of Foot. He held the titles of Baron Dartmouth (1675) Viscount Totnes (1675) Earl of Plymouth (1675).Born about 1657 Died 17 Oct 1680 Tangiers, MoroccoAge 24 of Natural Causes. His remains were returned to London and interred in Westminster Abbey.
Catherine was the daugther of Thomas Pegge (b1604)of Yeldersley and Catherine Kniveton. Thomas was son of Christopher Pegge of Yeldersley and Jane Eyre (not that Jane Eyre) daughter of Rowland Eyre of Hassup (family goes back to 1200's). Christopher was the son of Ralph Pegge of Shirley, buried in the Chancel at Shirley, will proved at Litchfield 13 May 1599. Ralph was the son of John Pegge of Shirley, buried chancel of Shirley, believed born 1508, will dated 1 Aug 1533, proved at Lichfield 1540, wife was Isabel.
I haven't got any direct links before that, but I will.
The only annomaly is the fate of the daughter who I have also heard died in infancy but may have entered a nunnery and lived to old age. One source suggests Catherine Fitzcharles, the daughter of Charles II and Catherine Pegge, was born about 1659 in Westminster. She died in 1759.