Providing professional development to busy principals is an ongoing challenge for many school districts. Lynn Public Schools in Massachusetts and the nonprofit Center for Artistry and Scholarship (CAS) in Boston partnered to provide professional development to 16 principals in the district. Linda F. Nathan, Taarini Goyal, and Evonne Alvarez describe what led to the program's success, despite the initial skepticism of principals assigned to participate. First, the district was willing to be vulnerable and trusted CAS to lead PD for their principals. CAS built trust with the principals by creating a safe space through in-person teaching modules and individual coaching without evaluation. The program was adaptable and responded to the CAS team's evolving understanding of principals' needs. Principals had opportunities to share with and learn from each other.