Seven Islands of Bombay: origin, reclamation and legacy

The islands and their characteristics

The group commonly cited as the seven original islands includes:

• Bombay Island (the central island around the Fort area)
• Colaba
• Old Woman's Island (also called Little Colaba)
• Mazagaon (Mazgaon)
• Parel
• Worli
• Mahim

Each island had its own shoreline, tidal channels and small fishing settlements, and together they sat within a broad natural harbour that encouraged trade and settlement.

History and land reclamation

The islands were inhabited long before European arrival by local fishing communities, commonly known as the Kolis, and later became a point of interest for Portuguese and British powers. The Portuguese called the place by a name that evolved into "Bombaim" and English usage later became "Bombay." Ownership and administration passed to the British East India Company in the 17th century, and the colonial administration began systematic efforts to link the islands.

From the 18th century onward a series of engineering projects — causeways, embankments and planned reclamations — progressively filled channels and converted marshes into buildable land. Notable early works blocked tidal inlets to prevent flooding; later large‑scale reclamations created broad stretches of urban ground used for docks, roads and residential areas. Over time the seven islands ceased to be visibly separate and became the contiguous southern part of present‑day Mumbai.

Urban development and importance

Joining the islands created a strategic deep‑water harbour that fostered maritime trade, finance and industry. The reclaimed peninsula became the site of administrative buildings, ports and later mills and commercial districts. This concentration of commerce and infrastructure helped Bombay emerge as one of India’s principal urban and economic centres. The city's later growth spread north and east onto further reclaimed and natural land.

Notable facts and legacy

Although the physical islands are no longer distinct, their names persist in neighbourhoods and historic districts. The process of reclamation shaped the city’s geography and ecology, replacing mangroves and tidal flats with urban fabric. The official name change from Bombay to Mumbai in the 1990s reflected local language and identity while the layered colonial and indigenous history of the seven islands remains central to the city’s origin story. For further background and maps, see Seven Islands of Bombay.

Distinction: The phrase "Seven Islands" refers to a historical configuration rather than a present geographic boundary; what once were separate islands are now integral parts of the continuous landmass called Mumbai.