Born in Cremona in the years immediately after 1550, Girolamo was the youngest of the two sons of Andrea Amati who would have continued his father's business. His elder brother, Antonio, was in fact born in about 1540 and, together with Girolamo, would have begun to assist his father in what at the time was still the only Cremonese workshop that dealt with the making of violins, violas and cellos. After Andrea's death in 1577, the two brothers collaborated for about ten years, until, in 1588, a dispute arising from economic issues caused their separation. For the following period, Antonio and Girolamo then adopted an individual label that did not jointly report the names of the two brothers, until, in 1607, the elder brother died suddenly and Girolamo decided to return to the old wording.
The viola housed in the Galleria Estense in Modena, one of the first modern contraltos ever made, can be dated to c. 1625, and may therefore be considered the exclusive work of Girolamo. The instrument is made on the same model as the famous "Stauffer" viola of 1615 and has come down to us in conditions of exceptional purity, including the presence, very rare on such ancient instruments, of the original neck. The opportunity to carry out in-depth studies on this viola led to the publication of the first volume of the series "Treasures of Italian Violin Making" (2014). In the period after c. 1610, Girolamo was assisted in his workshop by his son Nicolò, born in 1596 from his father's second marriage, who unfortunately did not survive the tragic plague of 1630.
