[1] He was a lecturer at Royal Holloway, University of London between 1916 and 1918, and briefly also taught at Aberystwyth during the same period.
In 1917 he got a position as sixth form master and Head of Department of Civics at the Royal Grammar School, Newcastle.
[2] Davies is today best known for his work on late medieval English administrative history, particularly the reign of Edward II.
In his 1918 book The Baronial Opposition to Edward II: Its Character and Policy, a Study in Administrative History, he argues that the administration of Edward II, though politically a failure, saw several important innovations in the field of royal administration, particularly through the influence of the king's favourite Hugh Despenser the Younger, and his father Hugh Despenser the elder.
The book came out shortly after Thomas Frederick Tout's The Place of the Reign of Edward II in English History (1914), which covered much of the same area.