Louis IX (25 April 1214 – 25 August 1270), commonly known as Saint Louis or Louis the Saint, was King of France from 1226 to 1270, and the most illustrious of the Direct Capetians. He was crowned in Reims at the age of 12, following the death of his father Louis VIII. His mother, Blanche of Castile, ruled the kingdom as regent until he reached maturity, and then remained his valued adviser until her death. During Louis' childhood, Blanche dealt with the opposition of rebellious vassals and secured Capetian success in the Albigensian Crusade, which had started 20 years earlier.