Who dated NN?

Tello Alfonso of Castile (1337 – October 1370) was the seventh of the ten illegitimate children of Alfonso XI of Castile and Eleanor of Guzman. He was a prince of Castile and First Lord of Aguilar de Campoo. In Spanish he is known as Tello de Castilla, Infante de Castilla; Señor de Aguilar de Campoo, de Vizcaya, de Castañeda y de Lara.