Which of these persons was a 10th century Archbishop of Canterbury?

Sigeric the Serious (died 28 October 994) was the Archbishop of Canterbury from 990 to 994. It is unclear whether the epithet "The Serious" originated from his learning, or if it derived from transliteration of his name into Latin as Serio.

Sigeric was educated at Glastonbury Abbey, where he took holy orders. He was elected Abbot of St Augustine's in about 975 to 990, and consecrated by Archbishop Dunstan as Bishop of Ramsbury in 985 or 986. He was transferred to the see of Canterbury in 990. He may have been a disciple of Dunstan's.

While Sigeric was an abbot, Ælfric dedicated a book of translated homilies to him. He also advised King Æthelred to found Cholsey Abbey in Berkshire in honour of King Edward the Martyr, as well as having Edward memorialised at Shaftesbury Abbey.

Sigeric died on 28 October 994. He was buried in Christ Church, Canterbury. His will left wall hangings to Glastonbury as well as a valuable collection of books to his church at Sonning.