Beginning in the latter part of the 20th century, and especially since the advent of No Child Left Behind, the roles and responsibilities of the elementary school principal have undergone significant expansion. While the primary function of the principal at one time may have been to serve as the manager of the physical plant of the school and as the supervisor of the instructional staff in a manner reminiscent of the factory boss, today's principals are now more often expected to serve as the leader of leaders and to focus their efforts on instruction and its improvement. These expanded expectations may well be beyond the capabilities of any one individual or office. This multi-site case study examines how instructional leadership happens in three urban ring elementary schools, how teacher leaders contribute to this work, and how the principals of these schools support the facilitation of distributing instructional leadership. The primary question that guides this study is: How does instructional leadership happen in these three schools? This is examined and reported on from both the principal's and the teacher's perspectives. [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/en-US/products/dissertations/individuals.shtml.]