There is no contemporary biography of Altfrid. He is first mentioned by name on 3 October 852, when he took part in a
council in Mainz as bishop of Hildesheim. According to the
Hildesheim Chronicle Altfrid died "rich in days" in 874, from which a year of birth of around 800 is assumed. He owned land in the
Harzvorland and in central
Essen (
Asnithi), which may have been inherited from his family, and it seems likely that he belonged to the
Saxon nobility, and may have been connected to the
Liudolfings, who, however, had no influence in Altfrid's foundation Essen Abbey (
Stift Essen) until after his death. He was apparently a monk at
Corvey Abbey before he was declared Bishop of Hildesheim in 851 in succession to
Ebbo, who died on 20 March of that year. Since Ebbo had been installed and removed several times as
Archbishop of Reims, Altfrid took the unusual step of repeating all consecrations and ordinations of his predecessor to avoid their invalidation. In 864, Altfrid moved the relics of Saint Marsus from
Auxerre to an unknown place in Saxony, most likely to Corvey Abbey. His sermon on the arrival of the relics survives. In addition, Altfrid laid the cornerstone of a new
cathedral in Hildesheim in 852, a three-aisled cruciform church with a crossing and transept. It was completed in 872 and was consecrated on 1 November 872 in the presence of four bishops and the Abbot of Corvey. Even before his consecration as bishop, Altfrid had been active in the foundation of several female religious communities. Between 845 and 847 he acquired the relics of
Saints Cosmas and Damian in Rome. Altfrid also supported the Saxon Count Ricdag in the foundation of the
nunnery at Lamspringe by procuring for it the relics of
Saint Hadrian from Rome. According to the Hildesheim Chronicle Altfrid also founded a Benedictine monastery on his own land in the Harzvorland, of which no further details of either location or duration are known. More important is Altfrid's other foundation,
Essen Abbey (
Stift Essen), on his property in Essen (
Asthnide) on the Hellweg. The first Abbess of Essen was his kinswoman Gerswith, often referred to as his sister, although there is no direct evidence of this. Altfrid built a chapel in Essen, dedicated to
Saint Quentin; (this was demolished in 1817). He also built a church for the canonesses, the
Stiftskirche, later known as the
Essener Münster and from 1958 as
Essen Cathedral. Altfrid was buried here after his death on 15 August 874, according to his wishes. A
Gothic tomb stands over his grave in the east crypt, which is named after him. Altfrid founded
Liesborn Abbey and a monastery for men at Osterwieck near Seligenstadt. ==Diplomat==