About 1200 the learned ecclesiastical stylist Saxo wrote a history of the Danish nation. It is generally accepted that Saxo intended to support monarchy and the contemporary reigning kings. The new perspective presented is how Saxo accomplished this task within the context of the Church. More specifically this investigation will treat Saxo's use of marriage law in the second part of the Gesta Danorum.

At the time of Saxo canon law was just on the point of being established as a coherent system. On this background Saxo interpreted freely the legitimacy of marriages of earlier kings, except when earlier writers had already established a tradition. Remarkably, Saxo declared the illegitimacy of all children of king Sven Estridsen, the founding father of the royal family. Saxo clearly placed this assertion with an end in view. His plan is on one hand suggested by the fact that no older or contemporary source supports this claim and on the other hand by the remarkable parallels in the comments on the irregularities of marriage of the two central royal ancestors, Sven Estridsen and Eric Ejegod.

In this respect it is interesting that among the later descendants of the ancestor of all kings, Sven Estridsen, who had according to Saxo no legitimate heirs, we find both the adversaries of the reigning king and the king. There is much to support the hypothesis that Saxo deliberately discredited all branches of the royal family except that of king Valdemar's by placing information about illegitimacy or uncertain origins.

This investigation supports the view that Saxo writes in favour of the newly established Christian monarchic order of succession. This was linked to the basic idea that only parents united in Christian marriage could have legitimate off-spring with right of inheritance, including right to succeed to the throne.

The political conflicts of the 12th century - as described by Saxo - were in fact family-internal conflicts. Saxo placed information which -within the context of canon law - supported the legitimacy of one specific line of descendants, king Valdemar the Great's. This suggests that the Church had something to offer a king bothered by members of his own family. Christian marriage might tone down the fight for succession.