Swedish jarls were powerful noblemen in Sweden. There usually was only one holder of the title at a time, second only to the King of Sweden. For special occasions, regional jarls outside of Sweden could be nominated as well. An example of this is Jon Jarl, who allegedly conducted pirate operations against Novgorod in the east. History According to Procopius, the Heruli, after having raided the European continent for several generations, returned to Scandinavia in 512 as a result of military defeats. As their old territory was now occupied by the Danes, they settled next to the Geats in present-day Sweden. No elaborate theory exists to explain how the word came to be used as a title. Arguably, their knowledge in interpreting runes also meant they were gifted in martial arts and, as they gradually integrated, eril or jarl instead came to signify the rank of a leader. As described in the Icelandic sagas, such as Rígsthula, a jarl was a sort of chieftain next in rank to the king in the function of Marshal or Duke of the King's Army. Under any circumstance, when jarls are finally mentioned in medieval documents, it clearly was a title signifying a leader ranked directly under the king. In Swedish history, Jarls are described as either local rulers or viceroys appointed by a king, ruling one of the historical Swedish provinces, such as Västergötland, Östergötland, or Svitjod. In Norway, the jarls apparently kept this role and the kings attempted to introduce one in each Fylke before the title was used exclusively on the Orkney Islands in the 14th century. In Sweden, however, the title was replaced by "duke" (Swedish 'hertig') in the 13th century. Before the title was discontinued, Swedish jarls were powerful men, such as Birger Brosa, Ulf Fase, and Birger Jarl (original patronym Magnusson), often the true rulers of the Swedish kingdom. Jarls of Sweden Birger Brosa, 1174-1202 Johan Sverkersson, 1202-120? Jon Jarl, ?-1206? Knut Birgersson, 120?-1208, killed in 1208 at the Battle of Lena Folke Birgersson, 1208–1210, killed in 1210 at the Battle of Gestilren Charles the Deaf (Karl Döve), 1210?-1220, killed at the Battle of Lihula Ulf Fase, 1220?-? and 1231–1240, died 1248 Birger Magnusson, 1248–1266, last jarl (Dux Sweciae) Regional jarls Jarls of Västergötland Ulf Tostesson Ragnvald Ulfsson (c. 1010–20), later jarl of Staraja Ladoga and Ingria. Father of king Stenkil of Sweden. Other Jon Jarl (possibly several