Arabia, during the time of Prophet Mohammad (saw), was a country without any central authority. It was a country far from the civilized nations of those days. At the time Prophet Mohammad (saw) was spreading Islam; asking people to turn away from worshipping idols to worshipping Allah (SWT), the Almighty, the All-Knower, and the Master.

In 6/7 AH (628CE), Prophet Mohammad (saw) dispatched several representatives to rulers and kings of different parts of the world, each with a letter in which he invited them to become Muslims and submit to Allah's (SWT) faith. All these letters had the same purport, that is, the invitation to monotheism and Islamic fraternity. Many of the letters were met with a favorable response whilst others were rejected.

In many cases, the messengers of Prophet Mohammad (saw) were badly treated and abused. But Prophet Mohammad (saw) was not worried by these setbacks. He was inviting people to the right path and a few setbacks could not deter him from propagating Islam.

Since Prophet Mohammad's (saw) mission was divine, in obedience to Allah's (SWT) command, consistent with human nature and meant to lead people to Allah's (SWT) path, it highly impressed such just, truth seeking people as al-Najashi (Negus), good Christian King of Abyssinia ( Ethiopia ), Muquqs, and others, so they submitted to Islam.

Research made on the collection of Prophet Mohammad's (saw) letters indicates that he sent 62 letters to kings, chiefs of tribes and clans, and heads of convents.

Of the kings to whom Prophet Mohammad (saw) had sent letters inviting them to Islam, one was Khosrow Parviz, the King of Iran (Persia). The letter was sent to him through Abdullah ibn Hudhafah.

In the Name of Allah, the Merciful, the Compassionate.

Truly I call upon you to obey Allah's command and convert to Islam. I am Allah's Messenger to all the people so that living hearts will be awakened and illuminated and so that infidels will have no excuses. Submit to Islam so you will be safe and immune, and if you disobey me and turn down my invitation, you will be blamed for the sins of the magi.

On receiving the letter, Khosrow Parviz ordered it to be translated. When it was translated, he noticed that the Prophet Mohammad (saw) had written his own name before king's and this proved too hard for him to digest. He tore the letter in fury, totally ignored Abdullah ibn Hudhafah and refrained from responding to the letter.

When Prophet Mohammad (saw) was informed of this act, he prayed: "O' Lord! You too tear apart his kingdom."

Khosrow Parviz wrote to Badhan, who was governor of Yemen, a Persian province: "It has reached my ears that a person has claimed Prophethood in Hijaz. Arrange to send two brave and courageous persons to him so that they may bring him to me as a captive."

Immediately Badhan sent Abadhaweih, one of his assistants, and a Persian officer called Kharkharah, with a warrant that required Prophet Mohammad (saw) to surrender himself to them and go with them to Khosrow Parviz. Badhan, however, asked his assistant to find out the truth about Prophet Mohammad (saw).

Abadhaweih and his companion traveled from Yemen until they arrived in Taif, which is about 90 km from Makkah. Its people told them that Prophet Mohammad (saw) was now in Madinah. The Taif people - who were not Muslims at the time and the Quraish were very pleased when they learned that the Persian emperor had ordered the arrest of Muhammad. They felt that Prophet Mohammad (saw) was now facing his most difficult test.

Clean-shaven but with large moustaches, the two officers from Yemen came to Prophet Mohammad (saw) in Madinah. Abadhaweih said to him: "Khosrow Parviz, the king of kings, has written to Badhan, the governor of Yemen, commanding him to send us to take you to him. If you comply, Badhan will write to the king of kings interceding on your behalf. This will spare you a great deal of trouble. If you reject his order, you know how powerful he is. He is sure to destroy you and your people as well as your country."

Prophet Mohammad (saw) did not like their appearance. He (saw) asked them who ordered them to shave their beards and their reply was: "Our Lord", meaning Khosrow Parviz. Prophet Mohammad (saw) said: "But my Lord has commanded me to wear a beard and to trim my moustache." He also asked them to wait till the following day when he was to meet them again. In the meantime, Prophet Mohammad (saw) received information through the angel Gabriel (Jabra'il) that Allah (SWT) had caused Khosrow Parviz to be killed by Shirweih, his own son, giving him the exact time of night and the date when Khosrow Parviz was killed in Persia.

Prophet Mohammad (saw) called in the Persian messengers and told them of the killing of their King. They said to him: "Do you realize what you are saying? Your arrest has been ordered for something much more trivial than this. Do you still wish us to write this down and inform governor Badhan of what you have just said?"

Prophet Mohammad (saw) replied: "Yes. Tell him also on my behalf that my religion and my kingdom will replace that of Khosrow Parviz and will sweep all before it. Tell him also that if he accepts Islam, I will give him what he has now under his authority and will make him a ruler in the area he now governs." Prophet Mohammad (saw) also gave Kharkharah a sack of gold and silver that was sent to him as a present by another king.

The two envoys left and went back to Yemen where they told Badhan of what Prophet Mohammad (saw) had said. He told them: "This is not the sort of thing a king would say. To my mind, the man is a prophet, as he claims. If he is, what he has just told you will come to pass. If it is true that Khosrow Parviz has been killed, the man is a prophet and a messenger. If not, we will make up our mind about what to do with him."

Presently Badhan received a message from Shirweih informing him that he had killed his father, Khosrow Parviz after he had adopted despotic measures against the Persian nobility. He also commanded him to ask his commanders to swear allegiance to him as the new King. He further asked him not to disturb Prophet Mohammad (saw) until he had received further instructions.

Badhan then realized that Muhammad was truly God's Messenger. He called Abadhaweih in and questioned him further about Prophet Mohammad (saw). The latter told him that Prophet Mohammad (saw) did not keep any guard to protect him from his people or from anyone else. "Nevertheless, I have never spoken to a man who has inspired me with awe as much as he does." Badhan was then certain that Muhammad was truly the Messenger of God and he communicated his conviction to his advisers and counselors. He declared that he wished to become a Muslim and they all joined him in accepting the message of the Prophet Mohammad (saw).

This was the beginning of the spread of Islam in Yemen. The majority of its population, Christians and Magians alike, started to accept Islam. They conveyed this to Prophet Mohammad (saw) and he sent them some of his companions to teach them the principles of Islam and instruct them in how to lead an Islamic life.

The tides of events, sometimes, foretell about the future developments in history. These prophecies get special importance if they are from the source of revelation. In such cases, we ought to receive such implications, and after pondering over them, we have to acknowledge them, and prepare for their occurrence. The appointment (al-Mab'ath) of Prophet Mohammad (saw) to prophetic mission was among the subjects which were foretold from long before.

Noble Qur'an explicitly states that 'the People of the Book read about him and his traits, and they are aware that their prophets have elucidated the appearance of such leader.'

"Those who follow the Apostle-Prophet, the Ummi, whom they find written down with them in the Tawrat and the Injeel, (who) enjoins them good and forbids them evil, and makes lawful to them the good things and makes unlawful to them impure things, and removes from them their burden and the shackles which were upon them..." ( Noble Qur'an, 7:157)

"And when there came to them a Book from Allah verifying that which they have, and aforetime they used to pray for victory against those who disbelieve, but when there came to them (Prophet) that which they did not recognize, they disbelieved in him..." ( Noble Qur'an, 2:89)

Therefore, the Jewish scholars, the Christian priests, and Arab geomancers knew about the emergence of Prophet Mohammad (saw) from the clues in the Testaments.

Based on these prophecies, when Prophet Mohammad (saw), in the 7th AH, wrote invitation letters to the powerful governors of the world and among them is Heraclius, the emperor of Byzantine of Eastern Roman Empire.

The Byzantine Empire is also known as the Eastern Roman Empire, for it was in fact a continuation of the Roman Empire into its eastern part. Heraclius was the ruler between 610 - 641CE.

Abu Sufyan ibn Harb a leader of the tribe of Quraish and the arch enemy of Prophet Mohammad (saw), by coincidence, he is in Syria (Shaam) on a business trip, when the Prophet Mohammad's (saw) letter of invitation reached Heraclius, the emperor of Byzantine of Eastern Roman Empire. Heraclius, at the time was in his court at Constantinople - modern day Istanbul or Jerusalem celebrating his victory over the Persians.

Note: Abu Sufyan ibn Harb become so called Muslim only after the conquest of Makkah in 630 CE (8 AH) and this incident is from around 628CE.

Heraclius read the letter through an interpreter and then asked the people in his court, to find out if there was someone in the city, who knew Prophet Mohammad (saw). Heraclius agent reached Abu Sufyan ibn Harb with his companions was brought into the court.

Heraclius: "What kind of family does Muhammad belongs to?" asked Abu Sufyan ibn Harb: "Noble family", replied

Heraclius: "Has there been a king in his family?" asked
Abu Sufyan ibn Harb: "No," replied

Heraclius: "Are the people who have accepted his religion poor or rich?" questioned again
Abu Sufyan ibn Harb: "The people of higher class are against him, and people of middle class and lower class support him and accept his religion", replied

Heraclius was now becoming more and more interested and he went on asking questions.

Heraclius: "Are his followers on the increase or decrease?"
Abu Sufyan ibn Harb: "Increasing", replied shortly

Heraclius: "Have you known him to tell lies"? asked
Abu Sufyan ibn Harb: "No, he is an honest person", admitted

Heraclius: "Does he ever go against his convents?" once again asked
Abu Sufyan ibn Harb: "Not so far. But we have to see whether he carries out the new agreement made between us and him", answered lengthily for a change

Heraclius: "Have you ever fought him in wars?" questioned
Abu Sufyan ibn Harb: "Yes", answered

Heraclius: "What has been the result?" asked, getting more and more interested
Abu Sufyan ibn Harb: "Sometimes we have won, sometimes he", replied

Heraclius: "What does he teach?" asked
Abu Sufyan ibn Harb: "Worship One God, join no partners with Him, carry out your prayers, be chaste, speak the truth and keep union with your relatives", answered

Even surprised at his own answer as it sounded like he was preaching Islam, Heraclius stood up and said, "If all you said is true, then I am sure that this Prophet's Kingdom will reach here where I am standing. I was certain that a Prophet was coming, but I didn't know that he would be born in Arabia. If I were to go there, I would embrace Islam and wash the Prophet's feet with my own hands."

This was the way in which Prophet Mohammad (saw) spread Islam. Prophet Mohammad (saw) impressed them by his truthfulness, honesty, noble character and dedication in the service of Allah (SWT). Prophet Mohammad (saw) did not compel people to accept Islam under threat of waging wars, nor did he compel people to accept Islam by the force of the sword. Prophet Mohammad (saw) fought only in defense, and only when the enemies waged war on him.