This qualitative, longitudinal study examines the perspectives on professional development of a group of exemplary, new secondary teachers of English Language Arts and Spanish (n = 4). This study explores the teachers' development through the lens of the "embodied understanding of practice" (EUP), a novel theoretical framework of professional development (Dall'Alba & Sandberg, 2006). Although the framework has been applied to medical students before, this study seeks to provide an empirical perspective on the professional development of exemplary, beginning teachers. This study investigates the teachers' evolving EUPs of teaching, the key influences shaping their "beliefs-in-action," the ways in which teachers have worked to better serve underrepresented students, and their professional development trajectories. The study is guided by three research questions: 1) How have exemplary, new teachers understood and enacted their teaching practice in classrooms over time?, 2) How have they understood and enacted teaching second-language learners and academic language (AL) over time?, and 3) What professional development trajectories have they followed? Teachers for each subject were selected based on their high level of performance as student teachers. Teacher surveys, teacher interviews, and key artifacts from their teacher education program (i.e., teachers' Performance Assessment for California Teachers and MA inquiry projects and classroom assignments) compose the main data to identify the teachers' EUPs. The teachers' Performance Assessment for California Teachers (PACT) is a teaching assessment that focuses on the main domains of teaching practice (Pechone & Chung, 2006). It targets a lesson cycle and features a video. It is analyzed through a standardized protocol that taps planning, instruction, assessment, reflection, and AL. PACTs were used in this study to investigate how exemplary, beginning teachers implement instruction and view their professional development as teachers of English Language Arts and Spanish as a Foreign Language or as a Heritage Language at the secondary level. Surveys and interviews of some of their teacher education program supervisors as well as program documents and a researcher's journal were used as secondary data. How participants make sense of their EUPs over time was explored with the use of interpretive research methods and was reported through both case study and cross-case analyses. Case studies explore each teacher's understandings more in depth. Cross-case analyses identify common themes among the teachers. Qualitative data analysis were used as they offer perspectives on the teachers' EUPs, as well as their key influences, and how their work contexts, in particular, have fostered or constrained their career development in particular ways. Substantive findings drawn from this study include: a) the EUP model applies to the study of educators, b) exemplary, new teachers appear to feature a multi-dimensional EUP, and not a single EUP, of being a professional teacher, as they put forth particular ontologically-, epistemologically-, and contextually-based understandings of their work and their professional roles, c) the teachers' deep understandings of teaching appear to have become more sophisticated over time, d) key influences on the teachers' EUPs are their work contexts, the Credential/MA program, their long-term placements as student teachers in diverse classrooms, significant mentors and role models throughout their early education years, and key colleagues, e) teaching contexts, and context-based challenges, seem to play a key role in shaping the teachers' EUPs and their developmental trajectories over time, f) in most cases, the teachers' EUPs of teaching second language learners are intertwined with those of teaching AL, and g) teachers exhibit and report signs of expertise development in their own teaching over time. Overall, the study finds that there are complex interactions between the exemplary, new teachers' life experiences, their teacher education program, and their work contexts. These interactions have propelled the teachers to develop in different directions, thus becoming particular types of teachers, as Dall'Alba and Sandberg (2006) and Dall'Alba (2009b) predict in their theoretical framework. All four teachers have faced an adverse job market for teachers. Nicole demonstrates professional growth through taking on a range of new, leadership roles while working at a small, diverse urban school. Sarah demonstrates resilience and a continued commitment to her profession and working with diverse learners by successfully navigating changing work sites every year as a beginning teacher, working through the effects of severe budget cutbacks in the state. Erin's development encompasses personal and professional growth in taking pride in her abilities to advance diverse students' skills as native Spanish speakers and enhance their life-coping skills, while balancing challenging personal and professional demands. Adriana, as a mature professional, demonstrates professional growth in her role as a minority teacher teaching about intercultural understanding and diversity to her mostly White, rural students. Implications for enhancing teacher education and teacher education policy, as well as future research on teacher development, are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]