Final answer:
The Safavids reached their height under Abbas I, who implemented significant reforms and strengthened the empire both militarily and economically.
Step-by-step explanation:
The Safavids reached their height under the leadership of Abbas I, who ruled from 1587-1629. During his reign, the Safavid Empire experienced its peak military, political, and economic power. Abbas I implemented significant reforms, such as modernizing the military and civil service, building the capital city of Isfahan, and fostering Persian Islamic art and architecture.