Threatening the nation's independence were renewed Haitian invasions. In March 1844, Rivière-Hérard attempted to reimpose his authority, but the Dominicans put up stiff opposition and inflicted heavy casualties on the Haitians. In early July 1844, Duarte was urged by his followers to take the title of President of the Republic. Duarte agreed, but only if free elections were arranged. However, Santana's forces took Santo Domingo on July 12, and they declared Santana ruler of the Dominican Republic. Santana then put Mella, Duarte, and Sánchez in jail. On February 27, 1845, Santana executed María Trinidad Sánchez, heroine of La Trinitaria, and others for conspiracy.