[5] During the 20th century, many of the inner suburban municipalities became unsustainable; in 1913 the first major unification took place when the municipalities of Cape Town, Green Point and Sea Point, Woodstock, Mowbray, Rondebosch, Claremont, Maitland, and Kalk Bay were unified to create the first City of Cape Town.

In 1927 the municipality of Wynberg was also merged with Cape Town, with the result that all of the Southern Suburbs were incorporated into the City.

Durbanville achieved municipal status in 1901, Goodwood in 1938, Parow in 1939, Bellville and Fish Hoek in 1940, Pinelands in 1948, Kuils River in 1950, Milnerton in 1955, Kraaifontein in 1957, Gordon's Bay in 1961, Brackenfell in 1970.

Also in 1987, an act of the House of Assembly allowed the creation of local councils for white communities in peri-urban areas.

Initially, in a period called the "pre-interim phase", the existing local authorities would become TMSs but their councils would be replaced by councillors nominated by the members of the negotiating forum.

In 1998 Parliament enacted legislation (the Municipal Structures Act) determining the final form of local government in post-apartheid South Africa.

[8] At the time of the 2000 election the northern boundary of the metropolitan area was also extended to include Philadelphia, Klipheuwel, and the surrounding farmland.

The current municipality covers Cape Point in the south-west, Gordon's Bay in the south-east, and Atlantis in the north, and includes Robben Island.

The remote Prince Edward Islands are deemed to be part of the City of Cape Town, specifically of ward 115.

A subcouncil does not have any inherent responsibilities in law, but it is entitled to make recommendations to the City Council about anything that affects its area.

The DA won Cape Town with an outright majority, and Peter Marais, also a senior member of the provincial NNP, became mayor of the unicity.

However, DA leader Tony Leon's attempt to remove Marais from his position in 2001 caused the disintegration of the alliance, and NNP came to ally with the ANC.

In 2004, after a dismal showing in the general elections that year, the NNP prepared for dissolution and merger with the ANC, and most of its councillors joined the governing party.

Despite the ID voting with the ANC, Helen Zille of the DA was elected executive mayor on 15 March 2006 by a very narrow margin with the support of the Multi-Party Forum.

The initially fragile position of this new DA-led coalition, also known as the Multi-Party Government, was improved in January 2007 with the introduction of the ID following the expulsion of the small Africa Muslim Party for conspiring with the ANC.

With the ID and DA together holding a firm council majority, several of the smaller coalition partners were dropped from the city government by the time of the 2009 general elections, including the ACDP and FF+.

Helen Zille left the mayorship the same year to take up the position of premier of the Western Cape, and Dan Plato became mayor.

The party extended its lead even further to win a two-thirds majority of the seats on the City of Cape Town council in the 2016 municipal elections, and De Lille was thus sworn in to serve a second term.

[25][26] The 2001 census divided the municipality into the following main places:[27] The planning districts are:[25] The City of Cape Town is also bounded by the Atlantic Ocean to the south and west.