Full Idea
Gödel proved the completeness of first order predicate logic in his doctoral dissertation of 1930.
Gist of Idea
Gödel proved the completeness of first order predicate logic in 1930
Source
report of Kurt Gödel (Completeness of Axioms of Logic [1930]) by Michal Walicki - Introduction to Mathematical Logic History E.2.2
Book Reference
Walicki,Michal: 'Introduction to Mathematical Logic' [World Scientific 2012], p.36