Palais Porcia, Renaissance palace in Innere Stadt, Vienna, Austria.

The Palais Porcia stands at Herrengasse 23 in Vienna's Innere Stadt, between Palais Kinsky and Palais Trautmansdorff and opposite Palais Harrach. Built from 1538 and finished in 1546, it is one of the few Viennese palaces still shaped by the Renaissance. Its inner courtyard keeps an early Renaissance arcade, with the coats of arms of Hofkirchen and Losenstein in the middle of the arcade walkway.

The site's first documented stone buildings date from the 15th century, on foundations reaching back to the Roman period. In 1538 treasurer Count Gabriel von Salamanca-Ortenburg bought the medieval structures and had them rebuilt with arcades into one Renaissance residence, completed in 1546 after his death. The Hofkirchen and Losenstein families, owners from 1592, began a remodelling in 1602 that added early Baroque detail to the facade and an ornate spiral staircase of Kaiserstein from Kaisersteinbruch. The palace survived the fire of 1683.

The palace now houses the Administrative Library of the Austrian Federal Chancellery, where government documents and archives are kept for research and official use. This shows how historic mansions have been transformed into centers for public administration and scholarship.

The library within the palace primarily serves government employees, though visitors with valid photo identification can access the reading room during regular hours. It is worth checking in advance which areas are open to the public.

The palace survived the destructive fire of 1683 that devastated much of Vienna, preserving its original importance to the city. Its foundations reach back to the Roman period, creating an architectural connection to Vienna's ancient roots.