The reign in Spain for this queen was from 1474 to 1504
[DOC] [TLE] Isabella I - Infoplease [PAR] Isabella I or Isabella the Catholic, 14511504, Spanish queen of Castile and 
Len ... At the death (1474) of her half-brother Henry IV of Castile, the succession 
to ... their reign in effect marked the beginning of the unified Spanish kingdom.