Yvelines is a department in the western part of the Île-de-France region in Northern France. In 2019, it had a population of 1,448,207. Its prefecture is Versailles, home to the Palace of Versailles, the principal residence of the King of France from 1682 until 1789, a UNESCO World Heritage Site since 1979. Yvelines' subprefectures are Saint-Germain-en-Laye, Mantes-la-Jolie and Rambouillet.