Ferdinand, Count of Flanders

Ferdinand of Portugal (1188–1233), fourth son of King Sancho I of Portugal, was born at Coimbra and became count of Flanders and Hainaut jure uxoris by marrying Countess Joan in Paris in 1212. Seized en route by Prince Louis of France over the Artois dowry, he was freed after concessions and joined the enemies of France.

Captured at the Battle of Bouvines in July 1214, he spent twelve years in French prisons while Joan ruled alone. Released by Blanche of Castile in 1226, he died at Noyon in 1233.