Beatrice of Castile

Beatrice of Castile (1242/1244–1303) was an illegitimate daughter of Alfonso X of Castile and Mayor Guillén de Guzmán. In 1253 she married Afonso III of Portugal, in a settlement of Castile's claims over the Algarve. Afonso was still married to Matilda II of Boulogne, who accused him of bigamy; in 1258 the Pope condemned him for adultery.

As queen Beatrice promoted Portuguese-Castilian rapprochement. She inherited her mother's estates and protected the monastery of Santa Clara at Alcocer.

After Afonso's death she quarrelled with her son King Denis, returned to Castile in 1282, supported Alfonso X against her half-brother Sancho, and was at her father's deathbed in 1284. She died in 1303 and was buried at Alcobaça.