County of Barcelona

The County of Barcelona was the Catalan state that grew from a Frankish border post into the core of Aragon, lasting from 801 to 1164. Charlemagne's men planted it as the southern shield of his empire, a march against the emirate of Córdoba; by the tenth century its counts stopped swearing to distant Frankish kings and ruled as hereditary lords, fighting the Moors and gathering the other Catalan counties by marriage and treaty. Barcelona's counts pushed their influence over the Pyrenees into Occitania while holding the line on the Ebro. The decisive marriage came in the twelfth century: Count Ramon Berenguer IV wed Petronilla, heiress of neighbouring Aragon, and in 1162 their son inherited both lands, joining Barcelona to Aragon in personal union. The county's history dissolves from that year into the Crown of Aragon, but Barcelona stayed its richest city, and the merged Catalan counties carried its laws forward as the Principality of Catalonia.