Rollo (Norman: Rou; Old Norse: Hrólfr; French: Rollon; c. 860 – c. 930 AD) was a Viking who became the first ruler of Normandy, a region in northern France. He is sometimes called the first Duke of Normandy. His son and grandson, William Longsword and Richard I, used the titles "count" (Latin comes or consul) and "prince" (princeps), respectively. His great-grandson Richard II was the first to officially use the title of Duke of Normandy.
He emerged as the outstanding warrior among the Norsemen who had secured a permanent foothold on Frankish soil in the valley of the lower Seine. After the Siege of Chartres in 911, Charles the Simple, the king of West Francia, ceded them lands between the mouth of the Seine and what is now Rouen in exchange for Rollo agreeing to end his brigandage, and provide the Franks with protection against future Viking raids.
Rollo is first recorded as the leader of these Viking settlers in a charter of 918, and he continued to reign over the region of Normandy until at least 928. He was succeeded by his son William Longsword in the Duchy of Normandy that he had founded. The offspring of Rollo and his followers became known as the Normans. After the Norman conquest of England and their conquest of southern Italy and Sicily over the following two centuries, their descendants came to rule Norman England (the House of Normandy), much of the island of Ireland, the Kingdom of Sicily (the Kings of Sicily) as well as the Principality of Antioch from the 10th to 12th century, leaving behind an enduring legacy in the histories of Europe and the Near East.
The name Rollo is generally presumed to be a latinisation of the Old Norse name Hrólfr – a theory that is supported by the rendition of Hrólfr as Roluo in the Gesta Danorum. It is also sometimes suggested that Rollo may be a Latinised version of another Norse name, Hrollaugr.
The 10th-century Norman historian Dudo records that Rollo took the baptismal name Robert.A variant spelling, Rou, is used in the 12th-century Norman French verse chronicle Roman de Rou, which was compiled by Wace and commissioned by King Henry II of England, a descendant of Rollo.