This chapter looks at the development of its concepts and a practice globally, considers how values, theories, and discourses in urban planning and design have at various times intersected and influenced those in heritage conservation. It examines some evolving approaches to city planning and design, explores their relationship to heritage conservation. Heritage conservation, an organized effort to protect cultural heritage, is deeply intertwined with modern city planning. Like city planning, heritage conservation has its roots in a post-Enlightenment era and the industrializing cities of Western Europe. Paradoxically, the large-scale destruction of historic urban fabric was accompanied by heritage conservation that celebrated its scientific and rational dimensions. On the one hand, heritage conservation was elevated to a moral obligation and a peace-building effort; on the other, the rise of the International Style as a universal form beyond the parochialism that led to the wars, sounded the death knell for vernacular and local urban forms and traditions globally.