The constituency was created as per the
Statute of Autonomy of Castile and León of 1983 and was first contested in the
1983 regional election. The Statute provided for the nine
provinces in
Castile and León—
Ávila,
Burgos,
León,
Palencia,
Salamanca,
Segovia,
Soria,
Valladolid and
Zamora—to be established as multi-member districts in the
Cortes of Castile and León, with this regulation being maintained under the 1987 regional electoral law. Each constituency is entitled to an initial minimum of three seats, with one additional member per each 45,000 inhabitants or fraction greater than 22,500. Voting is on the basis of
universal suffrage, which comprises all nationals over eighteen, registered in Castile and León and in full enjoyment of their political rights. Amendments to the electoral law in 2011 required for
Castilian-Leonese people abroad to
apply for voting before being permitted to vote, a system known as "begged" or expat vote () which was abolished in 2022. Seats are elected using the
D'Hondt method and a
closed list proportional representation, with an
electoral threshold of three percent of valid votes—which includes blank ballots—being applied in each constituency. The electoral law allows for
parties and
federations registered in the
interior ministry,
coalitions and
groupings of electors to present lists of candidates. Parties and federations intending to form a coalition ahead of an election are required to inform the relevant Electoral Commission within ten days of the election call—fifteen before 1985—whereas groupings of electors need to secure the signature of at least one percent of the electorate in the constituencies for which they seek election—one-thousandth of the electorate, with a compulsory minimum of 500 signatures, until 1985—disallowing electors from signing for more than one list of candidates. ==Procurators==