A series of disturbing events troubled Monteverdi's world in the period around 1630. Mantua was invaded by Habsburg armies in 1630, who besieged the plague-stricken town, and after its fall in July looted its treasures, and dispersed the artistic community. The plague was carried to Mantua's ally Venice by an embassy led by Monteverdi's confidante Striggio, and over a period of 16 months led to over 45,000 deaths, leaving Venice's population in 1633 at just above 100,000, the lowest level for about 150 years. Among the plague victims was Monteverdi's assistant at San Marco, and a notable composer in his own right, Alessandro Grandi. The plague and the after-effects of war had an inevitable deleterious effect on the economy and artistic life of Venice. Monteverdi's younger brother Giulio Cesare also died at this time, probably from the plague.