Санчо III
Gutierre Fernández de Castro (flourished 1124–66) was a nobleman and military commander from the Kingdom of Castile. His career in royal service corresponds exactly with the reigns of Alfonso VII (1126–57) and his son Sancho III (1157–58). He served Alfonso as a courtier after 1134 and as majordomo (1135–38). He was the guardian and tutor the young Sancho III from 1145. Before his death he was also briefly the guardian of Sancho's infant son, Alfonso VIII.