There are several possible explanations for the origin of this Olde French surname. It is almost certainly habitational, deriving either from the French "gadove" and translating as one who lived or worked on a river bank or similar muddy area, or it may be a "frenchified" form of the German Town of Gadow. In the latter case the definite article "La" would be applied to specifically denote one from that place in the same way that "Le Flamanc" was used in England to denote a person from Flanders, the name over the centuries, gradually developing into the modern "Fleming". The "Lagadu" name recordings in the various early spellings include Claude Lagade christened at Dommartemont, Merthe et Moselle on November 21st 1668, and Elizabeth Gadault christened on December 13th 1684 at Gugny-sous-Vaudemont, Merthe et Moselle. In 1718 Yvon Lagatdu was baptised at Guiupas, Finnisterre, she was the daughter of Alain (below). The various spellings are believed to include Gadault, Gadeaux, Lagade and Gadaud. The first recorded spelling of the family name is shown to be that of Alain Lagatdu, christened which was dated January 1st 1692 at Guiupas, Finisterre, France, during the reign of King Louis X1V of France - known as "The Sun King" 1643-1715. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.