The National Gallery has its origins in John Julius Argenstein's private art collection, which was acquired by the State in 1824. It was expanded with paintings from the British royal art collections and as a result it was felt that a special building was needed so that the works could be displayed properly. As a result, in 1838 the current building was built, which houses the complete collection. The building is neoclassical in style, within a rationalist conception that was adapted to the exhibition functions for which it was conceived. However, successive acquisitions have meant that the building has had to be extended, most notably in 1975, the first amplification, and in 1991 with the building of the Sainsbury's wing, which is dedicated exclusively to early Renaissance artists. The National Gallery has the largest collection of Italian paintings outside Italy. This collection was initiated during Sir Charles Eastlake's period as curator and who travelled to the Mediterranean between 1855 and 1865 to purchase the best works. Another important section is that of Flemish painting, which is largely thanks to Queen Victoria who donated a large part of her personal collection to the gallery. Consequently the National covers all styles and periods. There are only two exceptions: portraits are housed in the nearby National Portrait Gallery and modern works are now on display at the Tate Gallery. The paintings in the National are displayed chronologically. Its comprehensive collection, which covers very diverse facets of European art from the 15th century onwards, makes the National comparable to the other two great galleries of world art: the Louvre in Paris and the Prado in Madrid. All three galleries were founded at a similar time and all of them have an encyclopaedic design that comprises all artistic styles up to the present day.