Abstract (Elsevier)
We derive the magic square of Freudenthal, Rozenfeld, and Tits from the geometry of a special class of N =2 Maxwell-Einstein supergravity theories. We also show that all of these theories are obtainable by truncation of N =8 supergravity theories in various spacetime dimensions d , except for an “exceptional” subclass, unique for a given d , which is associated with with the exceptional Jordan algebra of 3 × 3 hermitian octonionic matrices.