Eastern Samar was the first area of the Philippines sighted by Magellan on March 16, 1521. The lofty mountains of Zamal as called by Magellan’s crew are the mountain ranges that separate the province from Western Samar and Northern Samar. The Spaniards, however, anchored at the tiny island of Homonhon on the southern side of the province.

During the early days of Spanish rule, the Province of Samar, (of which Eastern Samar was a part) was called “Ibabao”. It was under the political and ecclesiastical jurisdiction of Cebu. Samar was made a separate province from Cebu in 1768. From its capital, Catbalogan, the administration of the encomiendas in the eastern coast was controlled.

Samar was divided into three provinces, namely: Eastern Samar, Northern Samar and Western Samar, by virtue of Republic Act No. 4221. The Law was overwhelmingly ratified in a plebiscite on November 9, 1965.