This is a text for a junior and senior level courses in modern geometry and/or history of mathematics for mathematics majors as well as secondary education students (this book meets the state geometry standards for California, Florida, Illinois, New York, and Texas). A prerequisite for this book includes completion of the introductory calculus sequence. While there is minimal calculus content in the book, the study of proofs does become rather involved. It highlights from the history of geometry are intertwined with explanations on how to read and write proofs. This is the first book to present the works of Euclid and Hilbert in addition to other geometers in chronological order, all in an effort to show how the subject matter developed over time. It includes hints and both partial and complete solutions that are included at the end of the book as an aid for selected exercises. This book develops ideas with careful attention to logic and follows the development of the field through time. An Instructor’s Solutions Manual is available upon request.