Complex sentence: The EDU later merged with the Ethiopian Democratic Party and formed the Ethiopian Democratic Unity Party (EDUP), which later was one of the parties that joined to form the United Ethiopian Democratic Forces, one of the two largest opposition parties in Ethiopia.
Split into simpler sentences: The EDU later merged with the Ethiopian Democratic Party and formed the Ethiopian Democratic Unity Party (EDUP). EDUP is among the parties that joined together to form the United Ethiopian Democratic Forces, one of the two largest opposition parties in Ethiopia.