Gottlob Frege

From On Determinism, 1922 (rev. Nov. 1946) by Jan Łukasiewicz

I belong, with a few fellow workers, to a still tiny group of philosophers and mathematicians who have chosen mathematical logic as the subject or the basis of their investigations. This discipline was initiated by Leibniz, the great mathematician and philosopher, but his efforts had fallen into oblivion when, about the middle of the nineteenth century, George Boole became its second founder. Gottlob Frege in Germany, Charles Peirce in the United States and Bertrand Russell in England have been the most prominent representatives of mathematical logic in our own times.

POLISH LOGIC 1920-1939
editor Storrs McCall
Oxford 1967, pages 19-20.