Halsten Stenkilsson (English exonym: Alstan; Old Icelandic: Hallstein) was King of Sweden from c. 1067 to 1070. The son of King Stenkil and a Swedish princess, he became king some time after his father's death (1066), and he may have ruled together with his brother Inge the Elder.
The date of his death is not known. but took over a highly volatile situation. While he was clearly a Christian like his father and brother, his influence may have been limited, since Adam relates that Christianity was so disturbed that the bishops appointed by the Archdiocese of Bremen did not even dare to travel to Sweden.). However, the king "A" could also be Håkan the Red. His co-rulership with his brother Inge is also mentioned in the Hervarar saga.