The son of a Graz sculptor, Fischer went to Rome at fourteen or fifteen and stayed until 1686, trained in the Schor workshop and moving in a circle that included Bernini and Carlo Fontana. He came back to Austria with something no local master builder had: a scholar's command of antiquity. He set it down in 1721 in Entwurff Einer Historischen Architectur, a folio of engravings he said had taken him sixteen years — not a neutral survey but an argument, made as Habsburg court architect, that imperial magnificence had historical warrant. Ennobled in 1696, he built the Winter Palace of Prince Eugene, Schönbrunn, the Court Library in Vienna and the Kollegienkirche in Salzburg. In 1715 he beat Johann Lucas von Hildebrandt to the Karlskirche commission. He died in Vienna in 1723; his son finished it.
