Constantine the Great vs Ruhollah Khomeini

Constantine defeated his rival Maxentius at the Milvian Bridge near Rome. According to tradition, Constantine saw a vision of a cross in the sky with the words 'In this sign, conquer.' The victory made Constantine the sole ruler of the Western Roman Empire and led to his conversion to Christianity.

Constantine and his co-emperor Licinius issued the Edict of Milan, granting religious toleration to all religions in the Roman Empire, including Christianity. The edict ended the persecution of Christians, restored confiscated church property, and established Christianity as a legally recognized religion.

Constantine defeated his co-emperor Licinius at the battles of Adrianople and Chrysopolis, ending the Tetrarchy system. He became the sole ruler of the entire Roman Empire, reuniting the Western and Eastern halves under his control. This reunification was the last time the Roman Empire was united under a single ruler.

Constantine convened the First Council of Nicaea, the first ecumenical council of the Christian Church, to resolve the Arian controversy over the nature of Christ. The council produced the Nicene Creed, affirming the divinity of Christ and establishing a unified Christian doctrine. Constantine presided over the council.

Constantine dedicated the city of Constantinople (modern Istanbul) as the new capital of the Roman Empire, built on the site of the ancient Greek city of Byzantium. The city was strategically located on the Bosporus strait, controlling trade routes between Europe and Asia. It became the capital of the Eastern Roman Empire for over a thousand years.

Khomeini was exiled from Iran after criticizing the Shah's White Revolution and granting of diplomatic immunity to US personnel. He settled in Najaf, Iraq, and later in France, where he continued to organize opposition to the Shah.

Khomeini led a popular revolution that overthrew the Shah's regime. He returned to Iran in February 1979 and established an Islamic Republic based on his doctrine of Velayat-e Faqih (Guardianship of the Jurist), with himself as Supreme Leader.

Khomeini supported the seizure of the US Embassy in Tehran by student militants, who held 52 American diplomats hostage for 444 days. The crisis deepened the rift with the US, led to economic sanctions, and consolidated Khomeini's power.

Khomeini led Iran through an eight-year war with Iraq, which began with an Iraqi invasion. The war resulted in hundreds of thousands of casualties and massive economic destruction, ending in a stalemate. Khomeini accepted a UN ceasefire in 1988.

Khomeini issued a fatwa calling for the death of author Salman Rushdie for his novel 'The Satanic Verses', which he deemed blasphemous. The fatwa led to international controversy, diplomatic tensions, and attacks on Rushdie's translators.