German architect. A bondsman and the son of a poor family, he was self-taught and became adviser to the Dukes of Württemberg on artistic and technical matters. He knew none of the Mediterranean languages but had trained his eye by looking at the architecture of foreign courts. In 1568, with Georg Gadner, a privy councilor, he drew up a set of building regulations for Württemberg. From 1537 he was in the service of Duke Ulrich VI of Württemberg (reg 1537-50) and from 1550 in that of Duke Christopher (reg 1550-68); after the latter's death Tretsch spent the last years of his own life working for Duke Ludwig VI (reg 1568-93). Tretsch's main work is undoubtedly the Altes Schloss (1553-68), the ducal palace in Stuttgart, on which he collaborated with Blasius Berwart I (active 1553-1590). The work started with rebuilding the medieval middle section of the Schloss, the Dürnitzbau, which was completed in 1560 with the duchess's chambers. In the same year an outside staircase was constructed in front of the courtyard façade of the Dürnitzbau, probably to designs by Berwart. The building of the three new courtyard ranges began in 1557. In 1559 Tretsch submitted a plan for the new (south) wing of the Altes Schloss, which was to include a chapel. The Schlosskapelle was the first Protestant church in the duchy of Württemberg; the sight-line for the church is mentioned in 1557. Tretsch was also involved in many other projects for the dukes. His expertise was particularly in demand for the reinforcement and extension of the fortresses at Hohentwiel (1552-56; 1561-64), Hohenurach (1561-65) and Schorndorf (1565). In addition, he drew up plans for the ducal palaces at Göppingen (1557-65), Pfullingen (1563) and Schloss Neuenstadt (1565) on the Linde. //