In 899, when Arnulf died, Hatto became regent of Germany, and guardian of the young king, Louis the Child, whose authority he compelled Zwentibold, king of Lorraine, an illegitimate son of Arnulf, to recognize.
When trouble arose between Conrad and Henry, duke of Saxony, afterwards King Henry the Fowler, the attitude of Conrad was ascribed by the Saxons to the influence of Hatto, who wished to prevent Henry from securing authority in Thuringia, where the see of Mainz had extensive possessions.
The legend of the Mouse Tower at Bingen is connected with Hatto II., who was archbishop of Mainz from 968 to 970.
This Hatto built the church of St George on the island of Reichenau, was generous to the see of Mainz and to the abbeys of Fulda and Reichenau, and was a patron of the chronicler Regino, abbot of Priim.
Heidemann, Hatto I., Erzbischof von Mainz (Berlin, 1865); G.
Hatto I >>
Borrell entrusted him to the care of a Bishop Hatto, under whose instruction Gerbert made great progress in mathematics.
In this duke we may certainly recognize Borel, who, according to the Spanish chroniclers, was count of Barcelona from 967 to 993, while the bishop may probably be identified with Hatto, bishop of Vich or Ausona from about 060 to 971 or 972.
Two of the Babenberg brothers were killed, and the survivor Adalbert was summoned before the imperial court by the regent Hatto I., archbishop of Mainz, a partisan of the Conradines.
His chief adviser was Hatto I., archbishop of Mainz; and during his reign the kingdom was ravaged by Hungarians and torn with internal strife.
Among these men were Hatto I.
Hence they had done everything they could to prevent the dukes from extending their authority, and as the government was carried on during the reign of Louis the Child mainly by Hatto I., archbishop of Mainz, they had been able to throw considerable obstacles in the way of their rivals.