Unbalanced growth or outward expansion of one neighbor may necessitate an administrative decision to merge (see urban sprawl).
Some cities (see below) that have gone through amalgamation or a similar process had several administrative sub-divisions or jurisdictions, each with a separate person in charge.
The former consisted of only the territorial limits of the city of Rio de Janeiro, formerly the Federal District as Brazilian capital until 1960 when it was moved to newly built Brasília.
In the early 1970s, the various towns, villages, and townships surrounding Metropolitan Toronto that were undergoing suburbanization were amalgamated into various new municipalities; among them Mississauga and Vaughan.
Later, the provincial government of Mike Harris undertook an extensive province-wide program of municipal mergers between 1996 and 2002.
In the Bavarian town of Ermershausen, citizens occupied the town hall to resist the merger with Maroldsweisach – unsuccessfully, although Ermershausen was reconstituted as an independent municipality in 1994 – and Horgau, also in Bavaria, successfully appealed its merger with Zusmarshausen to the Constitutional Court of Bavaria (Bayerischer Verfassungsgerichtshof).
[4] In 2003, several administrative cities (kota administratif) in Indonesia were merged back to the parent regencies, due to the Government Regulation no.
[7] Portugal was one of the first countries in the world to make an enlarged modern administrative reform, particularly during the 19th century.
In 1832, during Portuguese Civil War, a law from Mouzinho da Silveira, minister from the liberal government-in-exile (which then ruled only in the Azores) simplified the public administration, and reduced the number of municipalities to 796.
In 1836, after the liberal victory, Passos Manuel, minister from the government of the Marquess of Sá da Bandeira made a profound administrative reform which reduced significantly the number of municipalities, fixing it to 351.
Another series of mergers, this time also including cities and market towns, reduced the total number of municipalities from roughly 1,000 in the early 1960s to 278 in 1974.