Humbertus was consecrated before 824. He was martyred by the Danes, and later venerated as Saint Humbert. His death is uncertain; he may have died 845 or 856, or possibly in November 869.
After Humbertus, there was an interruption with the episcopal succession through the Danish Viking invasions in the late 9th and early 10th centuries. By the mid-10th century, the sees Elmham and Dunwich had been united under Bishop Eadwulf.