Prophet Muhammad ﷺ and Contemporary Rulers

Heraclius of Byzantine Rome

Heraclius was the Byzantine emperor of Eastern Rome, who rose to power when he overthrew the evil ruler, Phocas, who was disliked by his people. Heraclius adhered to the religion of Christianity, particularly a Chalcedonian sect of it. He entered religion-based diplomatic ties with other kingdoms in the Balkans, such as the kingdom ruled by the Serbs and the Croats. He also tried uniting the various sects of Christianity together, but this idea was rejected.

Prophet Muhammad ﷺ wrote a letter to Heraclius in the sixth year of Hijrah, inviting him to Islam. The companion, Dihyah al-Kalbi took the letter and handed it to the Byzantine governor of Basrah, who then delivered it personally to Heraclius. This letter read;
In the Name of Allah, the Most Beneficent, the Most Merciful. From Muhammad, the slave of Allah and His Messenger, to Hercules, king of the Byzantines. Blessed are those who follow true guidance. I invite you to embrace Islam so that you may live in security. If you come within the fold of Islam, Allah will give you double reward, but in case you turn your back upon it, then the burden of the sins of all your people shall fall on your shoulders. Say (O Muhammad: O people of the Scripture (Jews and Christians), come to a word that is just between us and you, that we worship none but Allah, and that we associate no partners with Him, and that none of us shall take others as lords besides Allah. Then, if they turn away, say: ‘Bear witness that we are Muslims’.

Heraclius was stunned. He ordered the merchants of Arabia who were present in Rome, one of them Abu Sufyan ibn Harb (who was still a Non-Muslim back then) to examine the letter and tell him more about this Prophet. Heraclius asked Abu Sufyan if the Prophet ﷺ ever told a lie, and Abu Sufyan, even though he didn't like the Prophet ﷺ back then, admitted that the Prophet ﷺ had told many truths and had never lied before. But when Abu Sufyan told Heraclius that the number of Muslims were increasing every day and none of them had every left, Heraclius took this as a sign of true faith. He declared that he would have joined the Prophet ﷺ in Madinah, but he did not do so, as he was afraid that his kingdom would rebel against him and kill him. As he said this, there was a lot of commotion, and Abu Sufyan and the Arabian traders were ordered to leave.

Heraclius never converted to Islam, in fact he did fight against some Muslim armies in later years, to try and regain his territories. But he eventually lost. Despite all of this, it is known that he had a very great respect for Prophet Muhammad ﷺ in his heart, even if he died as a disbelieving ruler. The Prophet ﷺ said that the Byzantines would remain strong until the loss of His letter. And this was true, the Byzantines became weak and the letter was stolen by Ferdinand Alfonso, a ruler who attacked Al-Andalus and even Byzantine territories.