Harold the king ordered this memorial to be raised in honour of Gorm his father and Thyra his mother, the Harold who won all Denmark and Norway and made the Danes Christians.[7]
In one sense the larger stone is King Harold's own memorial. It is to be observed that the inscription credits the King with three notable achievements: the unification of Denmark, the conquest of Norway, and the introduction of Christianity. The allusion to the winning of Denmark doubtless refers to the suppression of revolts, perhaps more specifically to the annihilation of the viking realm and dynasty south of the Danework (about 950).[8] In his attitude toward his southern neighbours Harold continued the policy of Gorm and Thyra: wars for defence rather than for territorial conquest.
It is said that King Harold became a Christian (about 960) as the result of a successful appeal to the judgment of God by a zealous clerk named Poppo. The heated iron (or iron gauntlet, as Saxo has it) was carried the required distance, but Poppo's hand sustained no injury. Whatever be the truth about Poppo's ordeal, it seems evident that some such test was actually made, as the earliest account of it, that of Widukind of Corvey, was written not more than a decade after the event.[9] The importance of the ordeal is manifest: up to this time the faith had made but small headway in the Northern countries. With the conversion of a king, however, a new situation was created: Christianity still had to continue its warfare against the old gods, but signs of victory were multiplying. One of the first fruits of Harold Bluetooth's conversion was the Church of the Holy Trinity, built at Roeskild by royal command,[10]—a church that long held an honoured place in the Danish establishment. In various ways the history of this church closely touches that of the dynasty itself: here the bones of the founder were laid; here, too, his ungrateful son Sweyn found quiet for his restless spirit; and it was in this church where Harold's grandson, Canute the Great, stained and violated sanctuary by ordering the murder of Ulf, his sister's husband.
In the wider activities of the tenth century, Harold Bluetooth played a large and important part. About the time he accepted Christianity, he visited the Slavic regions on the south Baltic coasts and established his authority over the lands about the mouth of the Oder River. Here he founded the stronghold of Jomburg, the earls and garrisons of which played an important part in Northern history for more than two generations. The object of this expansion into Wendland was no doubt principally to secure the Slavic trade which was of considerable importance and which had interested the Danes for more than two centuries.[11] As the Wendish tribes had practically no cities or recognised markets, the new establishment on the banks of the Oder soon grew to be of great commercial as well as of military importance.
During the same period Harold's attention was turned to Norway where a difficult situation had arisen. Harold Fairhair, the founder of the Norse monarchy, left the sovereignty to his son Eric (later named Bloodax); but the jealousies of Eric's many brothers combined with his own cruel régime soon called forth a reaction in favour of a younger brother, Hakon the Good, whose youth had been spent under Christian influences at the English court. King Hakon was an excellent ruler, but the raids of his nephews, the sons of Eric, caused a great deal of confusion. The young exiles finally found a friend in Harold Bluetooth who even adopted one of them, Harold Grayfell, as his own son.[12]
The fostering of Harold Grayfell had important consequences continuing for two generations till the invasion of Norway by Canute the Great. With a force largely recruited in Denmark, the sons of Eric attacked Norway and came upon King Hakon on the island of Stord where a battle was fought in which the King fell (961). But the men who had slain their royal kinsman found it difficult to secure recognition as kings: the result of the battle was that Norway was broken up into a number of petty kingdoms and earldoms, each aiming at practical independence.