Urban planning has its origins in ancient civilizations like Harappa and Mohenjo-Daro which had deliberately planned cities. In classical times, Greek philosophers like Hippodamus laid out cities in orthogonal grids. During medieval times, many new towns were built in Europe to gain power. In the 19th century, overcrowded industrial cities led to new ideas like Ebenezer Howard's Garden Cities which proposed self-sufficient towns surrounded by greenbelts. In the 20th century, planners like Le Corbusier proposed concepts like the Radiant City with high density apartment blocks separated by open spaces. Chandigarh was influenced by these ideas and became a model new town in post-colonial India