Alfonso was born in Zamora. He was the only son of King Ferdinand II of León and Urraca of Portugal.[1] His father was the younger son of Alfonso VII of León and Castile, who divided his kingdoms between his sons, which set the stage for conflict in the family until the kingdoms were re-united by Alfonso IX's son Ferdinand III of Castile.[2]
In 1191, he married Theresa of Portugal,[15] daughter of King Sancho I of Portugal and Queen Dulce of Aragon.[16] Between 1191 and 1196, the year in which their marriage was annulled, three children were born.
On 17 November 1197 he married infanta Berengaria of Castile, daughter of King Alfonso VIII of Castile and Leonor of England. Five children were born of this marriage.
Alfonso IX of León died on 24 September 1230. His death was particularly significant in that his son, Ferdinand III of Castile, who was already the King of Castile also inherited the throne of León from his father. This was thanks to the negotiations of his mother, Berengaria, who convinced her stepdaughters to renounce their claim on the throne.[42] In an effort to quickly consolidate his power over León, Ferdinand III abandoned a military campaign to capture the city of Jaén immediately upon hearing news of his father's death and traveled to León to be crowned king. This coronation united the Kingdoms of León and Castile which would go on to dominate the Iberian Peninsula.
1. Gerli 2003, p. 54.
2. Shadis 2010, p. xix.
15. Echols 1992, pp. 400-401.
16. Fernandes Marques 2008, pp. 62, 87.
42. Shadis 2010, p. 3.
https://en.wikipedia.org/wiki/Alfonso_IX_of_León
--

Berengaria (Castilian: Berenguela; nicknamed the Great (Castilian: la Grande); 1179 or 1180 – 8 November 1246) was queen regnant of Castile[1] in 1217 and queen consort of León from 1197 to 1204. As the eldest child and heir presumptive of Alfonso VIII of Castile, she was a sought after bride, and was engaged to Conrad, the son of Holy Roman Emperor Frederick I Barbarossa. After his death, she married her cousin, Alfonso IX of León, to secure the peace between him and her father. She had five children with him before their marriage was voided by Pope Innocent III.
Berengaria was born either in 1179[2][3] or 1180,[3][4] in Burgos.[3] She was the eldest daughter of King Alfonso VIII of Castile and Eleanor of England and sister of Mafalda and Henry I of Castile.[5]
1. The full title was Regina Castelle et Toleti (Queen of Castille and Toledo).
2. de la Cruz 2006, p. 9.
3. Martínez Diez 2007, p. 46.
4. González 1960, pp. 196–200.
5. Martínez Díez, Gonzalo (2007). Alfonso VIII, rey de Castilla y Toledo (1158-1214). Gijón: Ediciones Trea, S.L. p. 46-53. ISBN 978-84-9704-327-4.
https://en.wikipedia.org/wiki/Berengaria_of_Castile
--
Her marriage to Conrad never took place:
Conrad II (February/March 1173 – August 15, 1196) was duke of Swabia from 1191 to his death and Duke of Rothenburg (1188–1191). He was the fourth son of Frederick III Barbarossa and Beatrice I, Countess of Burgundy, and brother of Henry VI, Holy Roman Emperor.
He was engaged to Berengaria of Castile in 1187, and knighted by Alfonso VIII of Castile in 1188. The marriage was never completed. At first it was delayed due to her young age. By 1191, she resisted the marriage and sought an annulment of the marriage treaty.[1]
In 1191, Conrad was present in Rome for the coronation of his brother, Henry VI, Holy Roman Emperor. He then joined the Norman campaigns in Sicily in 1191 and 1194. A chronicler described Conrad as "a man thoroughly given to adultery, fornication, defilement, and every foulness; nevertheless, he was vigorous and brave in battle and generous to his friends."
Conrad was murdered in Durlach in 1196, allegedly by the husband of a woman he had raped. Another story says that Conrad was bitten in the eye by a virgin he was attempting to rape, and that he died of the resulting infection.
https://en.wikipedia.org/wiki/Conrad_II,_Duke_of_Swabia
--