Le Corbusier's ideas and works constitute the greatest single influence in the development of architecture in the 20th century. His passionately expressed philosophy has had an enormous effect on the urban fabric and the way we live. Weaving through his long and prolific life are certain recurrent themes - his perennial drive towards new types of dwelling, from the early white villas to the Unite d'Habitation at Marseilles; his evolving concepts of urban form, including the Plan Voisin of 1925; and his belief in a new technocratic order.