What did King Henry do to make the barons hate him so much?

King Henry III of England faced significant opposition from the barons due to his perceived mismanagement and favoritism towards foreign advisors, which alienated the English nobility. His heavy taxation to fund wars and extravagant spending also fueled discontent. Additionally, his failure to adequately involve the barons in governance and his reliance on a small circle of trusted allies led to a breakdown in trust, sparking the Barons' Revolt and increasing animosity towards his rule.