Alwyn Ann Ruddock was a respected British historian, best known for her research on the English voyages of the 15th-century explorer John Cabot. Cabot and other navigators of the time were trying to find North American lands reached by Icelanders in previous centuries.

During the war years, she taught English and European courses in the history department of what became Southampton University.

In 1946, Ruddock moved to Birkbeck. After the publication of her Italian Merchants and Shipping in Southampton, 1270-1500 (1951), Alwyn was appointed reader in history, and in due course was elected fellow of the Society of Antiquaries of London (1960) and of the Royal Historical Society.

Alwyn retired from Birkbeck in 1976 and eventually finished a draft of her book on Cabot, but destroyed it before starting a second draft. Which was not completed. Prior to her death in  2006 she left strict orders that all research papers were to be destroyed at her death.