Cosimo III de' Medici, Grand Duke of Tuscany
Thanks to his richness, Count Giacomo Brivio lent money to many notable people of his time. In 1710 he was fideiussor of Cosimo III de' Medici, Grand Duke of Tuscany. In 1713 Giacomo became Lord of Montevecchia, the village of his ancestors, and in 1716 famous composer Antonio Vivaldi dedicated him a dramma per musica, Arsilda, regina di Ponto.