A Sea King was the Viking

Viking

The term Viking is customarily used to refer to the Norse explorers, warriors, merchants, and pirates who raided, traded, explored and settled in wide areas of Europe, Asia and the North Atlantic islands from the late 8th to the mid-11th century.These Norsemen used their famed longships to...

 name for a powerful pirate chieftain.

They could be actual kings of Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

 (such as Yngvi

Yngvi and Alf

Yngvi and Alf were two legendary Swedish kings of the House of Yngling.According to Ynglingatal, Historia Norwegiae and Ynglinga saga, Yngvi and Alf were the sons of Alrik....

 and Jorund

Jorund

Jorund or Jörundr was a Swedish king of the House of Yngling. He was the son of Yngvi, and he had reclaimed the throne of Sweden for his dynasty from Haki .Snorri Sturluson relates...

), Denmark

Denmark

Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

 or a Norwegian

Norway

Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

 kingdom, and sons of kings, such as Refil

Refil

* According to Hervarar saga, Refil was a son of the Swedish king Björn Ironside and the brother of its next king Erik Björnsson. He appears in Hervarar saga and in Nafnaþulur. According to these sources, Refil was a great warlord and a sea-king who would have lived in the early 9th century...

, but they could also be men "without roof" like Hjörvard

Hjörvard

Hjörvard was the name of several characters in Norse mythology.#Hjörvard Ylfing, see Granmar.#Hjörvard, who rebelled against Hrólf Kraki and killed him, see Heoroweard#Hjörvard, the son of Arngrim.#Hervor's name as a shieldmaiden....

 the Ylfing.

In the Norse sagas, such men without roof could be so powerful that they could subdue a country and make themselves kings. Two examples are Sölve

Sölve

Sölve was a sea-king who conquered Sweden by burning the Swedish king Östen to death inside his hall.The Heimskringla relates that he was the son Högne of Nærøy, and that he had his home in Jutland...

 who killed the Swedish king Östen

Östen

Eysteinn was the son of Eadgils and Yrsa of Saxony. He was the father of Ingvar. The Eysteinn tumulus in Västerås near Östanbro has been linked to King Eysteinn by some popular historians...

, and Haki

Haki

Hake, Haki or Haco, the brother of Hagbard, was a famous Scandinavian sea-king, in Norse mythology. He is mentioned in the 12th century Gesta Danorum, and in 13th-century sources including Ynglinga saga, Nafnaþulur, Völsunga saga...

 who killed the Swedish king Hugleik

Hugleik

Hugleik or Ochilaik was a Swedish king of the House of Yngling, according to the Ynglinga saga. He was the son of Alf and Bera.Some commentators assimilate Hugleik with his namesake, the Geatish king Hygelac...

. However, in both cases they ultimately lost due to lack of popular support.

List of sea-kings as given in the Nafnaþulur

Nafnaþulur

Nafnaþulur is a subsection of Snorri Sturluson's Prose Edda, the last part of the Skáldskaparmál. It is a listing in verse of names that may be used in poetry for various items, such as gods, giants, people, animals, and weapons...

1-5

Ali Ale the Strong Ale the Strong or Ole , in Scandinavian legend, belonged to the House of Skjöldung , and he was the son of king Fridleif of Denmark and a cousin of Helgi's... Asmund Atal Ati Atli Atli -Characters:* Atli, one of the names of the Norse god Thor* Atli in the Völsunga saga, believed to be a romanticized version of Attila the Hun* Atli Buðlason* Atli Hringsson* Atli Iðmundsson* Atli the Slender, a 9th-century earl of Sogn, Norway-Poetry:... Audmund Beimi Beimuni Beiti Budli Budli Buðli or Budli is the name of one or two legendary kings from the Scandinavian Legendary sagas.-Ásmundar saga kappabana:According to the Ásmundar saga kappabana, Buðli was a Swedish king, and the father of Hildr.... Byrvil Ekkil Endill Endill In Norse mythology, Endill is a jötunn, god or sea-king. He is attested in the Prose Edda list Nafnaþulur, and in various kennings.In Nafnaþulur, he is mentioned as only a name in a list of 75 sea kings. In Þórsdrápa his name appears in the kenning á Endils mó which means "onto Endil's moor" and... Frodi Eynef

Gaupi Gæir Gauti Gautrek Geitir Gestil Gjuki Gjúki Gjúki was the King of the Burgundians in the late 4th century until his death in or around 407. He was the father of Gundomar I, Giselher, and Gunther.... Glammi Gor Gudmund Gylfi Gylfi In Norse mythology, Gylfi, Gylfe, Gylvi, or Gylve was the earliest king in Scandinavia recorded. The traditions on Gylfi deal with how he was tricked by the gods and his relations with the goddess Gefjon.-The creation of Zealand:... Hagbard Hagbard Hagbard , the brother of Haki and son of Hamund, was a famous Scandinavian sea-king in Norse mythology. He is mentioned in Skáldskaparmál, Ynglinga saga, Nafnaþulur, Völsunga saga and Gesta Danorum... Haki Haki Hake, Haki or Haco, the brother of Hagbard, was a famous Scandinavian sea-king, in Norse mythology. He is mentioned in the 12th century Gesta Danorum, and in 13th-century sources including Ynglinga saga, Nafnaþulur, Völsunga saga... Half Harek

Heiti Hemlir Hiorolf Hjalmar Hjálmar - Current :*Þorsteinn Einarsson - Guitar and vocals*Sigurður Halldór Guðmundsson - Keyboards and vocals*Guðmundur Kristinn Jónsson - Guitar* Valdimar Kolbeinn Sigurjónsson - Bass* Helgi Svavar Helgason - Percussion- Former :... Hnefi Hogni Homar Horvi Hraudnir Hraudung Hraudung In Norse mythology, Hraudung was a human king and the father of Geirröd and Agnar according to the prose header of the poem Grímnismál from the Poetic Edda.... Hun Hunding Hunding Hunding is a municipality in the district of Deggendorf in Bavaria in Germany.... Hviting Hæmir Iorek

Kilmund Leifi Longhorn Lyngvi Mævi Mævil Meiti Moir Mysing Nori Næfil Ræfil Refil * According to Hervarar saga, Refil was a son of the Swedish king Björn Ironside and the brother of its next king Erik Björnsson. He appears in Hervarar saga and in Nafnaþulur. According to these sources, Refil was a great warlord and a sea-king who would have lived in the early 9th century... Randver Randver Randvér or Randver was, according to Sögubrot and the Lay of Hyndla, the son of Ráðbarðr the king of Garðaríki and Auðr the Deep-Minded, the daughter of Ivar Vidfamne... Rakni Reifnir

Rer Rodi Rokkvi Skefil Skekkil Solsi Solvi Sorvi Sveidi Teiti Thvinnil Vandil Vinnil Virfil Yngvi Yngvi and Alf Yngvi and Alf were two legendary Swedish kings of the House of Yngling.According to Ynglingatal, Historia Norwegiae and Ynglinga saga, Yngvi and Alf were the sons of Alrik....