Having a doctorate from both Oxford and Cambridge makes Andenas what Ghil'ad Zuckermann calls an "Oxbridge paradox".
Andenas belongs to the rare group of people who hold a "pair o' docs" (sounding like "paradox" but meaning "two doctorates"), a D.Phil.
In 2002–2003 he held the Chaire W J Ganshof van der Meersch under the Fondation Philippe Wiener–Maurice Anspach at the Université Libre de Bruxelles.
In 2005 he was a fellow of Netherlands Institute for Advanced Study in the Humanities and Social Sciences.
In 2008–2009 he delivered a series of lectures at l'École normale Supérieure, Paris om human rights and comparative law.