 Haymo became chancellor to the monastery, as is proved by his records of its transactions, which are still extant.It is probable that owing to his great learning he was also entrusted with the teaching of theology in the same monastery, but there is no positive proof of this.He had been living for only a short while in the Benedictine monastery at Hersfeld, perhaps as its abbot, when in the last weeks of 840 he was nominated to the Bishopric of Halberstadt.