Simplify the following text for a Grade 9 native English-speaking person.
Original: They consist of Santo Domingo de GuzmÃ n National District and three municipal divisions of Santo Domingo Province : Santo Domingo Norte ( Villa Mella Municipal District , etc. ) , Santo Domingo Este ( San Isidro Municipal District , etc. ) , and Santo Domingo Oeste .
Simplified: After his assassination in 1961 , Ciudad Trujillo became again Santo Domingo . The 1966 constitution named the city Santo Domingo de GuzmÃ n.