Elizabeth and Isabel

"A.C." inquires whether these names are not varied forms of the same name, and if so, what is the common origin of the two? Camden, in his *Remains*, has— "ELIZABETH, *Heb.* Peace of the Lord, or quiet rest of the Lord, the which England has found verified in the most honoured name of our late sovereign. Mantuan, playing with it maketh it Eliza-bella; and of Isabel he says 'The same with Elizabeth, if the Spaniards do not mistake, which always translate Elizabeth into Isabel, and the French into Isabeau.'"