Answer:
Oliver Cromwell (who overthrew Charles I) was the great, great, great grand-nephew of Thomas Cromwell (Chief Minister to Henry VIII).
Thomas Cromwell's sister Catherine was married to Morgan Ap Williams: a welshman who was believed to the great-grandson of Henry VIII's grand-uncle Jasper Tudor (Morgan's grandmother was believed to be Joan, an illegitimate daughter of Jasper).
Catherine and Morgan's son Richard took the name of Cromwell when he came to court under the sponsorship of his Uncle Thomas. Richard was the great-grandfather of Oliver.
[By the way: since Charles I was the great, great, great-grandson of Henry VII (Henry VIII's father & Jasper's nephew), this means that Oliver Cromwell and Charles I were distant cousins].
First answer by ID1467181693. Last edit by Rosewrites252. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 1 [recommend question].