General Notes

HENRY I, byname HENRY THE FAT, Spanish ENRIQUE EL GORDO, French HENRI LE GROS (b. c 1210 - d. July 22, 1274, Pamplona, Navarre), king of Navarre (1270-74) and count (as Henry III) of Champagne.  Henry was the youngest son of Theobald I of Navarre by Margaret of Foix.  He succeeded his eldest brother, Theobald II (Thibaut V) in both kingdom and countship in December 1270.  By his marriage (1269) to Blanche, daughter of Robert I of Artois and niece of Louis IX of France, he had one daughter, Joan, whom, by the Convention of Bonleiu (30 Nov 1273), he promised to one of the two sons of Edward I of England, Henry and Alfonso.  This would have led to a union of his dominions with English Gascony, but it came to nothing.  King Henry died in 1274; both the English princes died in the next decade and Joan was married in 1284 to the future Philip IV of France.  [Encylcopaedia Britannica]

Note: His birth year give above is obviously wrong, as his father was only 9 years old in 1210.  I will follow people in World Connect with 1244.