Complex sentence: Known as "La Masacre del Perejil" in Spanish, Trujillo started the massacre in 1937, claiming that Haiti was harboring his former Dominican opponents, Trujillo ordered an attack on the border, slaughtering tens of thousands of Haitians as they tried to escape.
Split into simpler sentences: Known as "La Masacre del Perejil" in Spanish, Trujillo started the massacre in 1937. Claiming that Haiti was harboring his former Dominican opponents, he ordered an attack on the border that slaughtered tens of thousands of Haitians as they tried to escape.