Enterprise Architecture is the discipline of managing the complexities of the Business-IT landscape. It has been around since the 1980's, when for the first time computers were connected in networks, and the already serious (and unsolved) problem of the complexity of computer programs for relatively simple business needs turned into the huge problem of large networks of them in complex business landscapes. In spite of many 'best practices' and 'frameworks' that have been introduced, Enterprise Architecture is not a great success. After thirty years, we still have the same problems. Chaos is still everywhere. Projects still fail far too often. In this book, (hidden) assumptions behind the existing approaches to enterprise architecture are challenged, and a more realistic perspective that helps us battle the complexities and unpredictabilities of today's Business-IT landscapes is described.