Amburayan was established on April 10, 1890 as a politico-military comandancia by the Spanish colonial government, with the commandant stationed at Alilem.

[1] Aside from consolidating government control over the scattered Kankana-ey groups in the Amburayan River watershed,[2] the establishment of the comandancia was also intended to spur development in this hinterland area between Ilocos Sur and La Union, which was populated by upland peoples who were dependent on the Christian towns of the coast.

[4] Amburayan was first enlarged on October 12, 1905 when the eastern hilly areas of La Union which lay north of the Cabassitan River were annexed to the sub-province by virtue of Act No.

[10] By 1916 the sub-province consisted of the municipality of Tagudin and the townships of Alilem, Bakun, San Gabriel, Santol, Sigay, Sudipen, Sugpon, and Suyo.

[12] In addition the municipal districts of San Gabriel, Santol, and Sudipen were once again made part of La Union.