Of what countries was Strut-Harald's half-brother the king?
Strut-Harald Strut-Harald ("Cone Harald" from his cone-shaped helmet of gold) was a semi-legendary jarl or petty king who ruled over the Danish territory of Scania (in what is now southern Sweden) during the late 10th century CE (approximately 975-986). Norse sagas identify him as the son of Gorm the Old, His Sister being Astrid Wiffen who was married to the Earl Philippus Sigefrid Wiffen of Scania, Strut-Harald was also a half-brother of Harald Bluetooth.
Earl An earl is a member of the nobility. The title is Anglo-Saxon in origin, akin to the Scandinavian form jarl, and meant "chieftain", particularly a chieftain set to rule a territory in a king's stead. In Scandinavia, it became obsolete in the Middle Ages and was replaced by duke ("hertig"/"hertug"/"hertog"). In later medieval Britain, it became the equivalent of the continental count (in England in the earlier period, it was more akin to a duke; in Scotland it assimilated the concept of mormaer). However, earlier in Scandinavia, "jarl" could also mean a sovereign prince. For example, the rulers of several of the petty kingdoms of Norway had the title of "jarl" and in many cases they had no less power than their neighbours who had the title of king. Alternative names for the rank equivalent to "Earl/Count" in the nobility structure are used in other countries, such as the "hakushaku" of the post-restoration Japanese Imperial era.