Prats-de-Mollo-la-Preste, "Pratis in Valis Asperis", the meadow in the wild valley, appears for the first time in 878. The first church is consecrated in 982; Of the monks of the abbey of Arles on Tech evangelizes the country. In 988, "Vila Pratis" becomes a county town of the Counts of Besalù who build a small palace there to stay during the summer. From 1242 to 1649, the Kings of Aragon protected the city and endowed it with privileges: abolition of certain taxes, creation of a university, delegation of deputies to the "Corts Catalans" first parliament known in Europe,, Free justice. These privileges ensured a continuous prosperity thanks to the development of the textile weaving industry, that of iron by the Catalan forges process, and the breeding.
In 1659, the city was attached to the kingdom of France following the signing of the Treaty of the Pyrenees. The city, headed by Joseph de la Trinxeria and its troop of armed volunteers "Angels of the Terra", will resist for more than 10 years the royal attempts to impose the tax on the so-called salt salt.
This attachment causes a deprivation of the valley deprived of its traditional outlets on Barcelona and Catalonia. Vauban directed the work of strengthening the city and the construction of the Fort which were part of the department's fortifications program.
In 1793, the population opened the doors of the city to the troops of General Ricardos who after invading the Roussillon were repulsed during the Battle of Peyrestortes.
In the 19th century, a rigorous francization, the creation of the road in 1870, the railway, led to the departure of many inhabitants facing the difficulties of mountain agriculture.
In 1939, 100,000 Spanish Republican refugees transit through Prats de Mollo, it is "La Retirada".
In 1940, torrential rainfall for more than three days caused the flooding of the Tech (L'Aiguat): roads, houses and factories were washed away. The economy of Prats is ruined.
Today thanks to the efficiency of the waters of La Preste, the city has managed to convert its economy to hydrotherapy and tourism.