Complex sentence: Pridi Phanomyong eventually returned to Siam on the 29 September 1933, not returning to government immediately he instead became an academic and founder of Thammasat University in 1934.
Split into simpler sentences: Pridi Phanomyong eventually returned to Siam on 29 September 1933, not returning to government immediately. He instead became an academic and founder of Thammasat University in 1934.