A military engineer from Urbino, Lanci was at the service of the Republic of Lucca between 1547 and 1557. In this period, he also worked for the French - who were occupying Montalcino on behalf of the Republic of Siena (1549) - and for Marcantonio Colonna in Paliano and Nettuno. He made surveys of the walls of Rome and the fortresses of Ancona, Ostia, and Civitavecchia for Pius IV (1499-1565, Pope from 1559). In 1557, he entered the service of Cosimo I de' Medici (1519-1574), who commissioned him to fortify just-conquered Siena and other Tuscan towns. The surveying instruments made for the Grand Duke's collection date from this period. He worked in the Maremma region as a hydraulic engineer, supervising the construction of the Sovana aqueduct and other infrastructure. Lanci took part in the improvement of Leghorn harbor (1566-1567), where he tested a dredger of his invention. He also distinguished himself as a civil architect - he seems to have designed the church of Santa Maria della Rosa in Chianciano - and he is mentioned as a perspectivist in Egnazio Danti's (1536-1586) commentary on Le due regole della prospettiva [The two rules of perspective] (Rome, 1583) by Jacopo Barozzi from Vignola (1507-1573).