The Helvetius dynasty originates from the Principality of Anhalt, in Germany. George Vigelius, one of its ancestors, was born in the Palatinate (Germany) and studied theology in the town of Basel (Switzerland), after which he was given the surname Swietser. In 1649, his eldest son, Johann Friedrich Swietser, moved to the United Provinces and changed his name into Johan Frederik Helvétius. In 1656, he took his doctorate of medicine at the university of Harderwyck Guelderland). He settled in Amsterdam and moved later to The Hague, where he had a lightning career. Three of his four sons studied medicine in Leyden: Jean-Balthasar, Philippe-Maximilien, and Joseph-Jean. Jean-Adrien, the second son of Johann-Friedrich, settled in Paris and took his doctorate of medicine at the university of Reims, using the pseudonym of Christian-Lebrecht Helvétius. He had a prosperous career. He was the father of Jean-Claude-Adrien Helvétius, who became also a successful physician and first physician to the queen of France. His grandson was Claude-Adrien Helvétius, who became a leading philosopher and writer.