The Jomsborg Vikings (Jomsvikings) were composed of selected warriors, adhered to a special codex, and were loyal only to their leader. Most records list as jarl of Jomsborg, Sigvald(i), son of petty king Strut-Harald of then Danish Scania. Sigvald died some time before 1010.R. Chartrand, Magnus Magnusson, Ian Heath, Mark Harrison, Keith Durham, The Vikings: Voyagers of Discovery and Plunder, Osprey Publishing, 2006, p.91,
