Duchy of Athens
Nerio I Acciaioli or Acciajuoli (full name Rainerio; died 25 September 1394) was the actual ruler of the Duchy of Athens from 1385. Born to a family of Florentine bankers, he became the principal agent of his influential kinsman, Niccolò Acciaioli, in Frankish Greece in 1360. He purchased large domains in the Principality of Achaea and administered them independently of the absent princes. He hired mercenaries and conquered Megara, a strategically important fortress in the Duchy of Athens, in 1374 or 1375. His troops again invaded the duchy in 1385. The Catalans who remained loyal to King Peter IV of Aragon could only keep the Acropolis of Athens, but they were also forced into surrender in 1388.