In the XVth century, you have to consider the land a bank of islands of the left bank land its isolated by water during the floods. The navigable channel was as close to the hillside of Checy. Modern levees built from the 16th century have permanently attached these islands on the left bank. At the end of the l’Ile aux Bourdon, rises the Chateau de L’Isle. 1348, Pierre Bourdon is Lord of the island and so named for his family.
The island became the property of the Groslot, 1475, L’Isle, mortgaged a mortgage in favour of Estienne Groslet (name later transformed into Groslot), a tanner merchant from Orléans, sold to Jehan Groslet, brother of Estienne. 1487, L’Isle is given to Jehan, son of Estienne.
Jacques the son of Jehan, gets the job of bailiff of Orléans, held between 1521 and 1545. He is also Knight, Chancellor of Alençon, Berry and Advisor to the King. 1530, Work on the Chateau de L’Isle begins. 1532, he acquired the farm of Haute-Isle and its feudal rights. 1535, he gets François 1er approval to build a drawbridge. 1545 , Jérôme succeeds Jacques, his father, to the office of bailiff of Orleans.
1548, the estate of Jacques Groslot extends over the considerable area of 1170 acres (482 ha) including L-Isle, the Haute-Isle, the Mont as well as the Ile-aux-Boeufs and many surrounding places. 1552, Jacques Groslot dies. His hotel in the Place de l’Etape in Orléans is still under construction. A Fervent supporter of the reform, Jérôme Groslot was arrested, as well as Condé, during the passage of François II to Orléans. The death of the king in the Hotel Groslot in December 1560 saves him from the execution of the conviction.
Orleans is occupied by the Protestant armies in 1562 and 1567. Jérôme Groslot then falls from grace and loses his burden of bailiff. He was sentenced to death in 1570 for the crime of lese-majeste. The edict of pacification of 1571 allows him to return to grace. It is authorized by Charles IX to hold a sermon in the Chateau de L’Isle. 1572, invited to Paris for the marriage of Henri de Navarre and Marguerite de Valois, Jérôme Groslot is a victim of the massacre of Saint-Barthélemy.
A Child on the death of his father, Jérôme II, becames an adult, dedicating his life to travel and writing. 1621, the estate goes to his two nephews, son of Louise Groslot, the wife of Samuel Puchot, a Norman gentleman and ‘agent general of the alleged reformed religion’. Louise Puchot, granddaughter of Louise Groslot, husband of Gédéon Richier manages his farms of Val d’Orléans. .
1751, Richier heirs sell the area of L’Isle to Charles Maximilien Midou, seigneur de Cormes. His brother Claude Louis Midou de la Chesnaye becomes owner a few years later. 1794, the son of the latter, also named Claude Louis, sells his domain to Pierre Luc François Jacques Mainville, negotiating with Indian fabrics in Orleans.
1803, Joséphine de Mainville, wife of Jean-Jacques Louet de Terrouenne, inherits part of the estate including the Chateau. 1829, the area of L’Isle, territory of Chécy, is awarded by decision of the Council of State, to the communes of Saint-Denis-Val and Sandillon. 1866, under the pressure of the flooded river rising over 150 m the chateau is largely destroyed as well as the farm.
1914, the Terrouenne family gave the castle to baron Henri Petiet. 1925, the castle is on the supplementary inventory of Historical Monuments, the castle is sold in 1961 to Mr. Bergeron and Mr. Denis Girault, then current owners.