This is the genealogy of architecture in the 20th century by Kenneth Frampton - the doyen of architecture history. His approach is impressively clear: he traces four lines that are recognizable as the powers that propel renewal in architecture. He structures his observations by focusing on the relevant periods in the following order: 1st, the Avant-Garde (1887-1986); 2nd, organic architecture (1910-1998); 3rd modern and national styles (1935-1998), and 4th, industrialization and prefabrication (1927-1990). His overview is not a lexical collection of chronological sequences. Instead, his insights stem from his confident eye for the history, theory and motives behind architecture. He also follows the steps of the great architects of the 20th century.