The Procuratori di San Marco were mostly, but not entirely, an honorific position, held for life. Formally, the procuratori di San Marco ranked second only to the doge.
The Republic of Venice changed continuously as conditions inside and outside of it changed, until it gradually found its final form in the 1300s and 1400s.
“Pregài o Pregadi” from the Dizionario del Dialetto Veneziano by Giuseppe Boerio.