Complex sentence: In August of 1916, Venizelist officials staged the coup prompting Eleftherios Venizelos to leave Athens, returning in October of 1916 and sets up a Greek government in Salonika and it is immediately recognized by the Allied governments.
Split into simpler sentences: In August of 1916, Venizelist officials staged the coup, prompting Venizelos to leave Athens. He returned in October of 1916 and set up a Greek government in Salonika which was immediately recognized by the Allied governments.