Sweyn was the son of Harold Bluetooth, who reigned in Denmark fifty years, from A.D. 935-985, and who in his old age became a Christian and strove to convert his subjects. But the ferocious warriors rebelled against him, and were headed by his unnatural son, Sweyn, who, although baptized, renounced Christianity, and fought to restore the bloodstained worship so congenial to the heart of a sea king. Defeated in battle, the unhappy father fled for his life, and fled in vain, for he was either murdered or died of his wounds.