Full Idea
Tarski's work is the earliest axiomatic theory of truth that meets minimal adequacy conditions.
Gist of Idea
Tarski's had the first axiomatic theory of truth that was minimally adequate
Source
report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Leon Horsten - The Tarskian Turn 01.1
Book Reference
Horsten,Leon: 'The Tarskian Turn' [MIT 2011], p.1
A Reaction
This shows a way in which Tarski gave a new direction to the study of truth. Subsequent theories have been 'stronger'.