Leo IV was a Byzantine Emperor who ruled from 775 to 780 AD. He was the son of Constantine V and succeeded his father after his death. Leo IV is known for his efforts to maintain the stability of the empire and for his support of the Orthodox Church, which was significant during a time of religious conflict. During his reign, Leo IV faced challenges from both internal factions and external threats, particularly from the Arabs. He is often remembered for his attempts to reconcile differences within the empire and for his military campaigns, which aimed to protect Byzantine territories. Leo IV's reign was relatively short, ending with his death in 780.