Based on research in Venetian and Prague archives, the study presents biographical data and family relationships of the musicians with the name Denzio. Already Pietro Denzio was an opera impresario; his marriage to Teresa, nee Peruzzi, gave birth to Antonio Alvise Denzio in Venice on 23 September 1689, who was later a tenor, Prague impresario and librettist. His sister Elisabetta, who died at the age of 21, was also a singer. In 1718, Antonio Denzio married Giovanna, nee Miola, with four of thein ten children born in Venice and six in Prague; daughter Marina Maddalena also became a singer. The witnesses for Antonio Denzio's wedding and the godfathers to his children were usually members of patrician families, i.e. Badoer, Gradenigo, Minotto and Venier in Venice, and university rector Wenzel Neumann, count Leopold Paar and others in Prague. Giovanni Maria Peruzzi, who left Prague together with his son impresario A. M. Peruzzi in 1725, after a conflict with Denzio, and went to Breslau, was probably Denzio's uncle. In 1730 he stood godfather to one of Denzio's daughters in Prague and died 1735 in Prague. The sources discovered also include a betrothal contract with a list of bride's marriage portion, and the testaments of Antonio Denzio's parents: Pietro drew up his testament in 1711 while Teresa drew up hers in 1733. Mother's testament indicates that Pietro Denzio and his son Antonio were in Regensburg in the autumn of 1733 and then, in December, again in Prague. Denzio and his family continued to stay in Prague even when he no longer worked as an impresario there: his tenth child was born there in July 1736. In Prague, he laid the foundations of the local public opera - type 'teatro impresariale' - which existed there until 1807.