At the time of Charlemagne, Maisons-Laffitte was just a little village, yet important enough to have a church. It was simply named Maisons and later Maisons-sur-Seine. The Parisian abbey of Saint Germain-des-Prés had received kings from the Valley of the Seine. The monks developed the land in the valley so Maisons became the centre of a large agricultural exploitation. When the Capetians appropriated the abbey's wealth, they put loyal knights there to protect the royal domain.

Toward 1050, Maisons became a fiefdom, ruled by the powerful family of the Poissys.

During the 12th century, a stone church was built, of which only the Romanesque bell tower remains - the "Ancienne église" - that had to be rebuilt during the 15th century after the damage caused in the 100 years' war. It remained a parochial church till 1872.

The Poissys were Lords of Maisons until the 15th century. Two sisters shared the fiefdom. It was unified in 1602 through the successive purchases of a Parisian family, members of Parliament - the Longueils - whose coats of arms became those of the town.

The most remarkable member of this family was René de Longueil, superintendent of Finances in 1650. Thanks to his wife's wealth - as heiress of several important Parisian financiers, he was able to get François Mansart to build him a château to match his high ambitions.

From 1634 to 1646, Mansart built one of the masterpieces of French architecture of the 17th century. René de Longueil added a "park" of about 100 acres. Louis 14th had it enclosed in 1658. the small roadways continued to spread until 1740. After that the wooded area were planted.

In 1777, the Marquis de Soyécourt -Longueils' heir - sold Maisons to a brother of Louis 16th, Earl of Artois. The latter settled his "English stable" - of about 30 horses - there but only from November to March, to feed and train them, although it was moved elsewhere by 1784.

Maisons was seized during the French Revolution. This national treasure was first bought by Lanchère - a supplier to the Army - then by the Marshal Lannes, and finally by the banker Jacques Laffitte, in 1818. He is the one who really initiated horseracing in Maisons. He dreamt of making it a training-centre similar to that of Newmarket's. He organized the first races on the meadows along the barks of the river Seine which became the racecourses that still exist today.

In 1833, Laffitte decided to sell the "Grand Parc du Château". He set it up as "a town for owners of country houses". Most of the owners were wealthy Parisians, who came for business or entertainment. Obviously, there were more modest owners as well. It was so successful that, within 10 years, the town was known as Maisons-Laffitte instead of Maisons-sur-Seine. This became the official name in 1882.

From 1843 on, the Parc developed still further when Maisons opened a station on the line "Paris-Rouen". The station drew a new population of residents- most working at Paris. During the Second Empire a whole new area developed around the station. That district became the heart of the town, linked to the "Parc" by the avenue de Longueil and to the old town by rue Masson and rue du Prieuré. A new church was built in 1872 and a new town hall in 1891 when the new racecourse was inaugurated in 1878, which stimulated the equestrian activities.

During the 20th century, the urbanization continued to develop to the West and to the South, at the expense of agricultural territory of which nothing remains today. The population rate grew, as more private properties were built plus the construction of many blocks of flats in the 50s, 60s and 70s.

The population grew from 13 074 in 1546 to 24 172 in 1968.