Achille Majnoni came from a noble family, he studied Civil Engineering at the Royal Technical Institute in Milan and started to work for the upper class and the Lombard aristocracy. He became friend with Umberto I and after the decree of the 30th March 1894 he was elected royal architect and started to deal with the royal residences. He made the rebuilding of the Royal Palace’s interiors in Monza. The private apartment of Umberto I is the result of the work of Majnoni, who adapted to the style of that age all the places located on the right of the Central Hall. With the new century, during the reign of Vittorio Emanuele III, Majnoni kept the public office, dealing also with the professional activity and keeping the eclectic style that characterized his activity in the period of Umberto I. As a member of the committee for the furniture of Italian embassies abroad, he dealt with those of Paris, Brussels and Bucharest. In 1925 he left the Royal Palace to retire in his house in Erba.