Ferdinand (Portuguese: Fernando, French and Dutch: Ferrand; 24 March 1188 – 27 July 1233) reigned as jure uxoris Count of Flanders and Hainaut from his marriage to Countess Joan, celebrated in Paris in 1212, until his death.

Louis' aim was to acquire his dead mother's dowry, a large piece of Flemish territory including Artois, which Joan's father had taken back by force after Isabella's death.

Released after this concession, Joan and Ferdinand soon joined the old allies of her father, King John of England and Emperor Otto IV, in an alliance against France.

[1] Ferdinand was to remain in French hands for the next 12 years, while Joan ruled alone.

He was released in 1226, by the French regent, Blanche of Castile, after the accession of her son Louis IX of France.