Devas holds a Master of Arts with Honours from the University of Oxford. Oxford is a collegiate university whose teaching traditions date back to the twelfth century, and his degree was conferred within this long-established academic setting.
Devas practised as a partner of Rowe & Maw, a London law firm founded in 1895 that was known for corporate, construction, pension, insurance, property, and employment work. Chambers & Partners nominated the firm as UK Law Firm of the Year in 2000.
Devas was admitted to the bar in England in 1975. Admission to the bar was the formal qualification that entitled a lawyer to practise in England.
In 2002 Rowe & Maw combined with the Chicago-based Mayer, Brown & Platt, creating Mayer, Brown, Rowe & Maw. The London practice later began to operate under the Mayer Brown name, dropping the legacy Rowe & Maw title.
