Del Rosario was born to Cipriano del Rosario and Severina Tongco in Binondo, Manila. He was a judge of the First Instance of Manila from 1888 to 1896. He was deported to Ceuta, Africa from 1896 to 1897 for alleged involvement in the revolution. Upon his return, he became a delegate of Surigao in the Malolos Congress in 1898 and delegate to the Philippine Assembly from 1909 to 1912.[1]