Complex sentence: Villa was in alliance with southern revolutionary Emiliano Zapata, who remained fighting in his own region of Morelos; however, the two revolutionary generals briefly came together to take Mexico City after Carranza's forces retreated from it.
Split into simpler sentences: Villa was in alliance with southern revolutionary Emiliano Zapata, who remained fighting in his own region of Morelos. The two revolutionary generals briefly came together to take Mexico City after Carranza's forces retreated from it.