Architectural styles are means to classify architecture in terms of techniques, materials, form, era, and characteristic features. Therefore, they are not all about aesthetic or visual features, but also about materials and techniques that enabled -and sometimes led to- these features -- what we can call engineering the aesthetics. This book is a trial to trace the development in these two lines in parallel. It overviews some of the most brilliant "architectural solutions" for genius architects, who utilized available materials and technologies, however primitive they were, to construct pioneering buildings that formed major threshold in the history of architecture. It also highlights the efforts of other pioneering architects in order to make use of newly discovered materials and technologies for creating pioneering styles that kept changing the face of architecture over the time.The book is especially helpful for architectural students and people who are interested in the history of art and architecture.