Principal professional learning is shifting in many districts in the United States of America away from didactic, central office-managed workshops to include more peer-led learning opportunities. Yet researchers have largely failed to examine issues of positionality and authority in principal professional learning, despite international scholarship that demonstrates the influence of micropolitics on the enactment of change. Using event analysis of a critical case study in an urban district in the northeast USA, we examine three chains of events. Principals and central office administrators used a variety of tactics -- cooperation, compromise, and co-optation -- to navigate overt and covert conflict during implementation of peer-led principal professional learning. Principals and central office administrators encountered micropolitics as they determined authority over the learning agenda, negotiated a redefinition of a new principal role, and co-constructed official spaces for peer-led learning. Findings provide lessons for educational leaders and those responsible for professional learning in districts with middle manager roles in any context, as well as suggesting that future research on the micropolitics of principal professional learning is warranted.