The Sangguniang Panlalawigan (English: Provincial Council), commonly known as the Provincial Board, is the Filipino language name given to the legislatures in Philippine provinces. They are the legislative branch of the province and their powers and responsibilities are defined by the Local Government Code of 1991. Along with the provincial governor, the executive branch of the province, they form the province's government.
During the early period of Spanish colonization, newly conquered areas were designated as encomiendas which were headed by an encomendero chosen by the Spanish from among the ranks of the powerful local nobles. Encomiendas were organized only for the purposes of collecting tribute that went in part to the Roman Catholic Church, the Spanish army, and to the Royal Treasury. Later on areas which were organized and given the designation of "province" (provincia) were led by an appointed alcalde who performed judicial, fiscal and executive functions. This system of government lasted for almost three hundred years until 1886 when a governor (gobernador) was first appointed in each of the eighteen existing provinces, relegating the alcalde to carry out only judicial functions.
American rule brought radical changes to the system of local government in the country. In 1901 the Philippine Commission enacted Act No. 83, known as the Provincial Government Act, which outlined the powers, responsibilities and composition of the provincial government. Each regularly organized province was provided a Provincial Board composed of three provincial officials: the governor, the treasurer, and a "third member" who in most cases was known as the supervisor. The governor in regularly organized provinces under civilian control were initially elected by municipal vice-presidents and councilors within the province through a convention held in the provincial capital every even-numbered year. As civil government took hold, the governorship was made elective. The composition of provincial boards were also later modified, with the treasurer and "third member" taken out and replaced by two members elected by popular vote. Not all provinces had the same type of government. Officials in specially organized provinces (those termed "Non-Christian provinces") were appointed by the Governor-General with the approval of the Philippine Commission until legislation gradually brought each of them in line with regularly organized provinces, that by the time of independence in 1946 all provinces had largely similar governments.