In medieval times, Sarasin or Sarrasine was a common name to describe the Saracen people. According to one version of the family history, the original head of the Sarasin family was actually a Saracen whom "Ludwig the Holy" brought back from a trip to Jerusalem, making him his friend and chancellor.
According to official records, the Sarasin family's descendants can be traced back to Regnaud, a magistrate and local patrician in the French city of Metz. Regnaud had four sons: Claude, Regnaud, Nicolas and Michel. The first-born, Claude, was made a hereditary nobleman by the Grand Duke Karl III of Lorraine in recognition of his loyal service. The Lorraine line is descended from him. The second eldest son, Regnaud, converted to Protestantism and also had four sons. The youngest, Gédéon, emigrated via Frankenthal, Strasbourg, Mariakirch and Colmar to Basel.
He and his son were given the freedom of the city on 10 March 1628. Jakob (1742–1802), who owned a silk factory and is considered to be the forefather of all the Basel Sarasins, was the fourth generation descendant of Gédéon. Together with his brother Lucas (1730–1802), the famous silk factory owner commissioned the construction of two large patrician houses in the Old Town (the White House and the Blue House), which now serve as a memorial to him.
The Blue House is currently the home of the Department of Commerce, Social Services and Environment for the Canton of Basel City.