James I of Aragon

James became King of Aragon and Count of Barcelona in 1213 at age five, raised by the Knights Templar after his father Peter II died fighting them at Muret during the Albigensian Crusade. That loss shaped everything: by treaty with Louis IX of France, he renounced the old Catalan holdings in Languedoc and Occitania - lands his family couldn't reclaim - and pivoted south. He took Majorca in 1231, Valencia in 1238, and carved out a Mediterranean empire that mirrored Ferdinand III's Reconquista gains in Andalusia. As a legislator he compiled the Llibre del Consolat de Mar, the maritime code that anchored Aragonese trade dominance, and as a writer he sponsored Catalan literature and penned the Llibre dels fets, a chronicle of his own reign. He died in 1276 after six decades on the throne, having turned loss into expansion and left Aragon facing the sea.