From the incipient and occasional town planning solutions of the late medieval period, to the Renaissance model of the "ideal city", there was primarily a process of conceptualisation of the dream urban environment. Order and utility were the main premises conforming to the structuring of a rational approach to knowledge and to the organisation of societies. The Baroque period developed and put extensively into practise the above referred to town planning schemes. They were carried out according to a defined economic, social and political context. Ports and capital cities became major elements in the urban-network. Their impressive growth was the reflection of a fast evolving society. Architectural excellence and regular spatial layout became the main town planning premises. In the eighteenth century, these concepts evolved to architectural embellishment and public utility. Apart from the unquestionable symbolic character of architecture, there was also an emerging concern with more wide-ranging issues: the social dimension of town planning was gaining an increasing relevance. The Enlightenment looked at the city as a coherent urban unit, which should be able to supply to its citizens a favourable environment. The Enlightened city was an ideological statement, which only made sense by its practical implementation. It was a conceptual model that determined a precise and operative town planning program. Utopia was gradually turning into an attainable vision of the city. Pombaline Lisbon, the New Town of Edinburgh and London's West End are three specific, yet comparable, town planning situations. In the sixteenth and seventeenth centuries, as large and important European cities, Lisbon, Edinburgh and London underwent a parallel process of urban growth and urban planning. They were all confronted with uncontrolled and deficient building, sanitary problems, traffic congestion and criminality. In Lisbon, the political and military circumstances determined the structuring of a sober and pragmatic architectural and town planning trend. The military engineering directed and developed the latter. At the eve of the earthquake of the 1st November 1755, the military engineers possessed simultaneously the knowledge and the skills to set up a major town planning venture. They built a new city, which was designed to promote progress. The New Town of Edinburgh was born from two concomitant premises: the need to give to the middle class a suitable residential area and the desire to improve the city's image. The model was indisputably the Enlightened city. Pombaline Lisbon and the New Town of Edinburgh depict a low cost and efficient urban ensemble that was also able to enhance their image in an international context. London served unquestionably as an example, given the spacious and agreeable new West End squares. London's expansion was a major financial enterprise, which used established schemes of building procedures. The aim was to improve London's urban conditions, yet the drive was its financial benefit. London's main town-planning procedures suggested already a new urban context: the industrial city.