Were Charles II of England and Isaac Newton alive at the same time?
Yes. Charles II of England and Isaac Newton were alive at the same time for 42 years, from 1642 to 1685.
Charles II of England was 12 when Isaac Newton was born.
Isaac Newton was 42 when Charles II of England died, aged 54.
Charles II of England
King of England, Scotland, and Ireland
Born 29 May 1630 (Julian calendar) · died 6 February 1685 (Julian calendar), aged 54
Isaac Newton
English mathematician and physicist
Born 25 December 1642 (Julian calendar) · died 20 March 1727 (Julian calendar), aged 84