The Italic League played an essential part in the balance of power subsequently pursued by the Florentine ruler Lorenzo de' Medici (1449–92); its only cracks were the Pazzi conspiracy, the Barons Conspiracy and the Salt War. The League provided enough stability to allow the peninsular economy to recover from the population loss and economic depression caused by the Black Death and its aftermath, leading to an economic expansion that endured until the first part of the 17th century. The League also enabled the creation of the first permanent embassies amongst the states of the Italian peninsula, in order to monitor compliance with the terms prohibiting supporting exiled dissidents, with "De Officio Legati" — what seems to be the first treatise on ambassadorship — written by Ermolao Barbaro in Venice in 1490, after he had served the "" in Burgundy and Milan.