What did kings gain through lay investiture?

Through lay investiture, kings gained significant control over the appointment of bishops and abbots, effectively increasing their influence over the Church and its resources. This practice allowed monarchs to ensure loyalty from church leaders, who often held substantial power and land, thereby reinforcing the king's authority and stabilizing his rule. Additionally, by appointing clergy, kings could use religious institutions to support their political agendas and consolidate their power within the realm.