Wallace Collection of the wealthiest families in Europe. They owned large properties in England, Wales and Ireland, and increased their wealth through successful marriages. Politically of lesser importance, the 3rd and 4th Marquess and Sir Richard Wallace became leading art collectors of their time. The Wallace Collection, comprising about 5,500 works of art, was bequeathed to the British nation by Lady Wallace in 1897. The state then decided to buy Hertford House to display the collection and it was opened as a museum in 1900. As a museum the Wallace Collection's main strength is perhaps its extraordinary array of 18th-century French art:
MOMus–Museum of Modern Art–Costakis Collection to assist art historians and theoreticians who wish to specialize in museology. As well as maintaining its permanent collection, the museum organizes periodic exhibitions. However, the pride and joy of the State Museum of Contemporary Art is the works in the Kostaki collection, which was bought by the Greek State on 31 March 2000 for 14,200,000,000 drachmas. This collection consists of 1,275 works of art (oil paintings, constructions, drawings etc.) The works are by well-known, avant-garde Russian artists like K. Malevich, V. Tatlin, V. Kandinsky, El. Lissitzky, and L. Popova, among others. The West became familiar with the Kostaki collection