Book excerpt: Understanding Teacher Identity: The Complexities of Forming an Identity as Professional Teacher introduces the reader to a collection of research-based works by authors that represent current research concerning the complexities of teacher identity and the role of teacher preparation programs in shaping the identity of teachers. Important to teacher preparation, as a profession, is a realization that the psychological, philosophical, theoretical, and pedagogical underpinnings of teacher identity have critical importance in shaping who the teacher is, and will continue to become in his/her practice. Teacher identity is an instrumental factor in teachers’ and the students’ success. Chapter One opens the book with a focus on the development of teacher identity, providing an introduction to the book and an understanding of the growing importance of identity in becoming a teacher. Chapters Two–Nine present field-based research that examines the complexities of teacher identity in teacher preparation and the importance of teacher identity in the teaching and learning experiences of the classroom. Finally, Chapter Ten presents an epilogue focusing on teacher identity and the importance, as teacher educators and practitioners, of making sense of who we are and how identity plays a critical role in the preparation and practice of teachers.