It is a reference book as it examines, from a global perspective, the work of the most prominent architects and the less important ones, and covers the history of architecture throughout the 20th century, starting with the 1889 Paris Exposition in 1889. At the same time, it provides all the necessary keys to understanding architectural trends at the beginning of the 21st century and sheds light on the impact on architecture of phenomena such as the two world wars, colonialism and major artistic and cultural movements. Without limiting himself to a simple, linear reading of the developments, the author analyses not only the mechanisms that promoted modernism but also the opposing trends, those that persisted thereafter. With the contribution of the rich material of hundreds of drawings, photographs, magazine and poster images, portraits of architects, film clips and other documents, the author places the radical development of architecture and urbanism of this period in the broader context of art, technology and critical theory.