Pierre-Paul Riquet spent his fortune on the Canal du Midi, died eight months before it opened, and left his heirs the canal and its debts

Pierre-Paul Riquet made his money collecting the gabelle, the salt tax, in Languedoc and supplying the army. He proposed a canal to join the Atlantic and the Mediterranean. A royal edict of 5 October 1666 ordered it built. Louis XIV made him Baron of Bonrepos in 1666, and in 1668 Riquet bought the canal itself as a seigneury at auction, becoming its lord. He put a large part of his own fortune into the works. When royal funding fell short late in the project, he sold most of his property to keep digging. He died on 1 October 1680 with about three kilometres left to dig (one source gives 4 October). His son Jean-Mathias finished the work, and the canal was inspected in May 1681. The children inherited the canal, its tolls and heavy debts. One account says the family needed until 1724 to clear the debts^†, the year the canal began paying its owners. The château at Bonrepos was sold at auction in 1836 after a disputed succession. In 1858 Napoleon III leased the canal for 40 years to the Chemins de fer du Midi railway company. Under a law of 27 November 1897 the French state bought the canal from Riquet's heirs. UNESCO listed it as a World Heritage Site in 1996. The village of Bonrepos-Riquet bought the château in 2007.