Pega (Old English Pēga) was the sister of St. Guthlac of Crowland — both children of the noble Mercian warrior family of the Guthlacingas (royal Icel descent).
When her brother withdrew to the Crowland fens in 699, Pega settled as a recluse at the nearby hermitage of what would become Peakirk ('Pega's church'), several miles from Guthlac across the fen. By the prescription of fen-anchoritic discipline they did not meet again in Guthlac's lifetime.
When Guthlac died on April 11, 714, his last instruction was that Pega be summoned to perform his burial. She came from Peakirk to Crowland, anointed and buried her brother per his instruction, and was the principal recipient of his Crowland goods (the Psalter and scourge that became the abbey's foundational relics).
Sometime after Guthlac's burial, Pega set out on pilgrimage to Rome (a not uncommon practice for Anglo-Saxon religious women of the early 8th century — see Bertha of Kent and Cuthburga). She died at Rome around 719 and was buried in a Roman church (variously identified in later tradition); her cult is preserved at her foundational Peakirk hermitage, which gave its name to the modern Cambridgeshire village.