On May 21, 1923, some 620 delegates representing 41 socialist political parties in 30 countries was convened in Hamburg, Germany to bring about the unification of the two Internationals.
Pada 21 Mei 1923, sekitar 620 delegasi mewakili 41 partai politik sosialis di 30 negara bertemu di Hamburg, Jerman dalam rangka penyatuan dua organisasi Internasional.