For almost five centuries one of the primary acts of European colonisers was the foundation of ports. In the nineteenth and twentieth centuries this phenomenon reached new heights, some ports becoming vast maritime-industrial complexes as well as veritable global cities. In order to develop these ports, colonisers had to confront specific geographical constraints linked to their natural environment. These ports were then defined by a number of flows and functions connected (or unconnected) to the colonial situation, which could either lead to their hyper-specialisation or, on the contrary, to the accumulation of a wide variety of different functions and activities. As interfaces between metropoles and colonies, as well as sometimes between different regions of particular empires, colonial ports were essential sites for implementing the colonising process, not only militarily but also on an economic, social and cultural level.