Tagino was a chaplain of Henry II, Duke of Bavaria, when, in 995, the See of Regensburg became vacant.
He was the duke's candidate for bishop, as well as the candidate of late bishop Saint Wolfgang, and he was elected by the congregation; but the Emperor Otto III appointed his own chaplain Gebhard and instead adopted Tagino into his own royal chaplaincy.
When Archbishop Gisilher died in 1004, the cathedral chapter elected as his replacement Walthard, but Henry II of Germany — the son of the old duke of Bavaria — overruled them and appointed Tagino, replacing him as his chaplain with Walthard.
[1] He also worked closely with Bernard I, Duke of Saxony, to (successfully) reconcile Henry of Schweinfurt with the Emperor.
With famous Thietmar of Merseburg in his train, he accompanied Queen Cunigunda from Augsburg to Gernrode and thence Magdeburg in 1004 after Henry had left for his Italian campaign against Arduin.