Hildebold was a Frankish churchman of the Carolingian era who became Bishop of Cologne around 787 and, when the see was elevated to a metropolitan archbishopric in 795, its first Archbishop. He served in that office until his death on 3 September 818, a tenure of more than three decades that spanned the height of Charlemagne's imperial consolidation of the Frankish church.
His prominence extended well beyond the diocese of Cologne. In 791 Charlemagne appointed him archchaplain and chancellor of the Imperial Council, effectively placing him at the head of the Carolingian court chapel and the imperial administration's clerical apparatus. So trusted was he that Pope Adrian I, at Charlemagne's personal request, granted Hildebold a dispensation from the canonical requirement that a bishop reside in his own see, enabling him to remain at court. He was the first witness to Charlemagne's testament drawn up in 811, and in 813 he co-presided with Archbishop Richulf at the great Synod of Mainz — convoked by Charlemagne and attended by thirty bishops and twenty-five abbots — at which he helped prepare the transition of rule to Louis the Pious. After Charlemagne's death in 814 Hildebold donated to the construction of his tomb at Aachen.
The elevation of Cologne in 795 was itself a signal achievement. The new province comprised six suffragan dioceses — Utrecht, Liège, Münster, Minden, Osnabrück, and Bremen — making Cologne independent of the older metropolitan sees of Mainz and Trier. Earlier, in 794, Hildebold participated as bishop in the Synod of Frankfurt, at which the assembled bishops condemned Adoptionism and took a stance against the Second Council of Nicaea's endorsement of the veneration of images, reflecting the tensions between the Frankish church and Constantinople that marked the late eighth century. He also took part in ecclesiastical life beyond synods: in 804 he served as principal consecrator of St. Ludger, the first Bishop of Münster and an eminent missionary to the Saxons, whom he had also met informally in 805.
Hildebold initiated an expansion of Cologne Cathedral, a building programme that his successors completed in 870. He died on 3 September 818 and was buried in the Abbey of St. Gereon in Cologne. A mosaic portrait of him survives in Cologne Cathedral. The Orthodox commemoration of pre-schism Western hierarchs of this period, recorded in the source 'Latin Saints of the Orthodox Patriarchate of Rome,' includes Hildebold among those venerated as saints of the undivided Church.
