King Afonso III of Portugal died on February 16, 1279 at the age of 68.
Peter III of Portugal died on May 25, 1786 at the age of 68.
King John I of Portugal died on August 14, 1433 at the age of 76.
King John V of Portugal died on July 31, 1750 at the age of 60.
King John II of Portugal died on October 25, 1495 at the age of 40.
King John III of Sweden died on November 17, 1592 at the age of 54.
Afonso III of Portugal died on 1279-02-16.
Sorry, but all I know is that he died in 1216, and was soon suceeded by Henry III
John IV of Portugal died on 1656-11-06.
John II of Portugal died on 1495-10-25.
John VI of Portugal died on 1826-03-10.
John V of Portugal died on 1750-07-31.