In 1838-9 an agreement was signed between the Sakalava king and Seyyid Said, King of Zanzibar, to give Said control over the Sakalava and Antankarana kingdoms; this agreement never came to the attention of Tsimiaro and resulted in no changes in governance on the ground. While in exile on Nosy Mitsio, Tsimiaro traveled to Ile Bourbon to conclude a treaty with the French on 5 April 1841 that guaranteed French protection for the Antankarana in exchange for rights to the islands of Nosy Mitsio, Nosy Faly, Nosy Be and Nosy Komba. The French intercession eventually repelled the Merina, allowing the king to reestablish the capital at Ambatoharaña, but more than 40 years passed before the entire Antankarana had permanently returned to the mainland. Upon his death, Tsimiaro was buried at his request in the Ankarana cave where he had taken refuge from the Merina. Other nobles are mainly entombed in the Islamic cemetery near Ambatoharaña. When the French agreed to recognize Malagasy sovereignty in 1862, they retained their claimed right to the Antankarana and Sakalava protectorates they had established. Tsimiaro was succeeded by his son, Tsialana II, (1883–1924) who was born on Nosy Mitsio in 1843. He collaborated with the French actively during their first expedition against the Merina (1883–85), and again during the successful expedition of 1895 that ended in French colonization of the island and the dismantling of the Merina monarchy. His son Abdourahaman would go on to fight on the side of the French during World War I. Tsialana II was succeeded by Lamboeny II (1925–1938), Tsialana III (1948–1959) and Tsimiharo II (1959–1982).