We study the growth of London's street-network in its dual representation, as the city has evolved over the last 224 years. The dual representation of a planar graph is a content-based network, where each node is a set of edges of the planar graph, and represents a transportation unit in the so-called information space, i.e. the space where information is handled in order to navigate through the city. First, we discuss a novel hybrid technique to extract dual graphs from planar graphs, called the hierarchical intersection continuity negotiation principle. Then we show that the growth of the network can be analytically described by logistic laws and that the topological properties of the network are governed by robust lognormal distributions characterising the network's connectivity and small-world properties that are consistent over time. Moreover, we find that the double-Paretolike distributions for the connectivity emerge for major roads and can be modelled via a stochastic content-based network model using simple space filling principles.