hidden Viollier, Henry-Francois-Gabriel (Frants -Gavriil, 1750 -1829), an artist, architect Viollier, Henry-Francois-Gabriel (Frants -Gavriil, 1750 -1829), an artist, architect. Viollier was of Swiss origin. He was in Russia from 1776. Till 1791 he served at the "Small court" of Grand Duke Paul Petrovich. Henry-Francois-Gabriel Viollier... more