ABSTRACT
In his thesis (published in 1928) Weil reproved and greatly extended a result of L.J.Mordell concerning the group of rational points on an elliptic curve. Known today as the Mordell-Weil theorem it remains a cornerstone of the subject now known as Diophantine Geometry and it is not too much to suggest that Weil was the first to recognize the existence and importance of this new subject matter. 1
