Complex sentence: In the 1890s Vuillard met the brothers Alexandre and Thadée Natanson, the founders of the Revue Blanche, and in 1892 did on their advice his first decorations ("apartment frescoes") for the house of Mme Desmarais.
Split into simpler sentences: In the 1890s Vuillard met the brothers Alexandre and Thadée Natanson, the founders of the "Revue Blanche". In 1892, on their advice, Vuillard painted his first decorations ("apartment frescoes") for the house of Mme Desmarais.