As a result of fundamental developments in economy, technology, and society the location behaviour of economic actors is changing. Traditional boundaries no longer hold. One category of locations confronted with these changes is seaports. Port-related activities are increasingly located in secondary centres at a distance from the port, resulting in the development of a ‘port network’. The rise of port networks is considered a new stage in the development of ports. To cope with the transition towards the new stage, port authorities need to revise their strategy. In this paper, the development of port networks is considered as an example of new spatial patterns and organisational structures in a borderless world. The factors behind the rise of port networks are identified and the contours of a new port strategy outlined. The theoretical model is illustrated by the case of Rotterdam.