Maria de Luna was queen consort of Aragon, as the spouse of King Martin I of Aragon, from his ascension in 1396 to her death in 1406. In the early years of Martin's reign, she served as regent of Aragon while her husband tended to affairs in Sicily, a kingdom to which he also had a claim.

The count of Barcelona was the ruler of the County of Barcelona and also, by extension and according with the Usages and Catalan constitutions, of the Principality of Catalonia as Princeps for much of Catalan history, from the 9th century until the 18th century. After 1164, with Alfonso II of Aragon and I of Barcelona, the title of count of Barcelona was united with that of king of Aragon, and after the 16th century, with that of king of Spain.