The Wallace Collection is one of London's hidden gems, a well-kept secret known only to the select few. Visitors to central London willing to bypass the bargains and bustle of Oxford Street and venture into the quiet streets and squares of Westminster will be well rewarded when they discover the delights of Hertford House, on Manchester Square.

A Dance to the Music of Time, by Nicholas PoussinThe Laughing Cavalier, by Frans Hals

Hertford House is a grand mansion, once home to the eminent Seymour-Conway family. It now houses probably the finest art collection ever amassed by five generations of a single family – four Marquesses of Hertford and Sir Richard Wallace (the illegitimate son of the last Marquess). With their mistresses and staggeringly wealthy wives, there was always a delicious air of scandal about the Marquesses of Hertford. That, along with their taste for the very best in art, for Velazquez, Rembrandt, Hals and Gainsborough, among many others, meant that the Wallace Collection has been a quiet success ever since it first opened to the public in 1900.

Wealthy landowners, the Seymour-Conway family had a long and impressive pedigree. They could trace their lineage back to Edward Seymour, Earl of Hertford, who was the brother of Jane Seymour, King Henry VIII's third wife and mother of King Edward VI. When the young Edward came to the throne, aged nine, the Earl of Hertford declared himself Protector of the boy King and the Realm.

Today however, the family is mainly known for its passion for art, particularly French art. The Wallace Collection is full of delicate Sevres porcelain, as well as lush portraits and landscapes by such French luminaries as Francois Boucher, Jean-Honore Fragonard, Antoine Watteau and Jean-Baptiste Greuze. Recent refurbishment sees the collection housed in sumptuous eighteenth-century French style, complete with silk wall hangings. The house is a pleasure to walk through.

The art collecting Marquessses of Hertford

1) Francis Seymour-Conway (1719-94)

The first Marquess had a distinguished diplomatic career.

2) Francis Ingram Seymour-Conway (1743-1822)

The second Marquess was a politician. His wife had a long, close friendship with the Prince of Wales (later King George IV).

3) Francis Charles Seymour-Conway (1777-1842)

The third Marquess, a somewhat debauched character, was the first serious collector in the family.

4) Richard Seymour-Conway (1800-70)

The fourth Marquess was probably the richest collector of his generation.

5) Richard Wallace (1818-90)

The illegitimate son of the fourth Marquess, Richard Wallace inherited both his father's interest in collecting and his vast fortune.

Lady Wallace, Sir Richard Wallace's widow, left the collection to the British nation, stipulating that it would be called the Wallace Collection in honour of her husband, and that nothing would be added to or taken away from the collection. Rest assured, if you wish to see a famous painting in the Wallace Collection – Perseus and Andromeda, by Titian, for example – it will be here.