Casanova at 63
This portrait of Casanova is said to be around 1788 when he was 63 years old and living in Bohemia at Dux (Duchcov). The engraving below appeared in the front of his only work of fiction, Icosameron (1788), a long and rambling utopian fantasy which had the helpful sub-title of "Or the Story of Edward and Elizabeth Who Spent Eighty-One Years in the Land of the Megamicres, Original Inhabitants of Protocosmos in the Interior of the Globe." It was first published in English, belatedly, in 1986.
Below is a possible portrait from around 1774 when Casanova was almost 50. It's a photo dating back to the 1930's of a painting by Venetian portrait painter Alessandro Longhi.
Casanova died in 1798 when he was 73.