The Lewis surname is Welsh.
Recorded in over fifty different spellings from Lewis, Lois, Lowis and Loisi, to such as Ludovici, Lotze, Lohde, and Ludwikiewicz, throughout Europe this great and ancient name is generally accepted as being of pre 5th century Frankish origins. It derives from the personal name "Hludwig", composed of the elements "hlud", meaning loud or famous, plus "wig", battle. As such it was borne by the founder of the Frankish dynasty, who was recorded in the surviving chronicles of the Roman Empire as Ludovicus and Chlodovechus, the latter form becoming the French Clovis, Clouis, and later Louis. Lowis or Lewis is the Anglo-French form of the name, and Lowis le Briton was entered in the Red Book of the Exchequer", Essex, in 1166. The surname first appears on record at the beginning of the 13th Century (see below). William Lewys was noted as a witness in the 1267 Fines Court Rolls of Suffolk. Confusingly in Wales, Lewis was also used as an anglicization of the Welsh name Llywelyn, from "llyw", leader, and "eilyn", likeness. Llewelyn ap-Madoc, alias Lewis Rede, was archdeacon of Brecon, Wales, in 1437. One of the most natable bearers of the name was the American explorer Meriwether Lewis (1774 - 1807), who, with William Clark, led an overland expedition from St. Louis to the Pacific Ocean in the early years of the 19th Century. The first recorded spelling of the family name is shown to be that of Robert Lowis, which was dated 1202, in the Pipe Rolls of Lancashire. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.