The Tondo Province annexed to this new district the towns of Cainta, Taytay, Antipolo and Boso-boso, while Laguna contributed the towns of Angono, Binangonan, Cardona, Morong, Baras, Tanay, Pililla and Jalajala.
This consisted of the towns of Antipolo, Bosoboso, Cainta and Taytay from the Province of Tondo; and the towns of Morong, Baras, Tanay, Pililla, Angono, Binangonan and Jalajala from the Province of La Laguna, with the capital at Morong.