Probably you’ve never studied Conversational Viking, let alone claimed to speak it.
However, the language of the Vikings, Old Norse, has influenced the development of English more than any other language besides French and Latin. In olden times the Swedes, Norwegians, Icelanders and Danes all spoke Old Norse, usually called the “Danish tongue.”
In the 11th century, Old Norse was the most widely spoken European language, ranging west with Leif Erickson’s colonization of Vinland in modern-day Canada, east with the Viking settlers on the Volga River in modern-day Russia and south with warriors battling in modern-day Spain, Italy and North Africa.
Four centuries after the Anglo-Saxons began emigrating from northern Europe, Danish Vikings began raiding Britain. They had begun settling down and plowing the land by the year 876. The 14 shires dominated by Danish law in northern and eastern England were called the Danelaw. In 1016, King Canute the Great became ruler of all England, even before he became king of his native Denmark.