 Mattias adored the arts, patronising Justus Sustermans, Volterrano and many other eminent artists.While in Germany, he acquired scientific instruments, such as dials, astrolabes and compasses; all of which he later deposited in the Uffizi.In later life, suffering from gout, he pondered re-assuming ecclesiastical garb; however, he fell ill and died in Siena on 11 October 1667 at 54 years of age.