The peace afforded by the Hudaybiya treaty gave an opportunity to the Prophet to propagate Islam throughout Arabia and enable Islam to embark upon its attempt to embrace all humanity. He sent ambassadors with his letters to Heraclius, the Byzantine emperor, Khosrow Parviz II, the Kisra of Persia[1], the kings of Egypt and Abyssinia, and to the chiefs of Yemen and Syria. These letters have been preserved and reproduced by Arab chroniclers.
The Byzantine emperor Heraclius (575 - 641 A.D.) woke up one day looking very distressed. His patriarchs immediately knew what was wrong with him. They said to him, “Yes! Last night, you saw in a vision that the King of the circumcized people has now attained power and authority. But we do not know any nation that circumcizes its sons other than the Jews, and they are already under your authority. Perhaps you should kill them all and set your mind to ease.’ As they were thus involved in their discussion, the emperor's governor over Bostra brought to the court an Arab.
“This man, O King,’ said the Governor, “is an Arab who is telling a very serious tale.’ Through an interpreter, Heraclius ordered the man to narrate the tale of what has happened in Arabia. The Arab said, “A man from among us has put forth a claim to Prophethood. Some people have followed him and some have not, and wars have been raging between both parties. Thus did I leave them behind.’ Heraclius ordered the man to be stripped. Once they stripped him, they found him circumcized. “This, by God, is what I saw in my vision,’ said Heraclius who ordered them to give him his clothes back. Then he called into his presence the chief of his police force and said to him, “Look everywhere throughout Syria and find me one of the people (Quraishites) of this man (meaning Muhammad).’[2]
Abu Sufyan narrates saying that he had come out in a trade caravan when they were intercepted by the chief of police of Heraclius who asked his group, “Are you from the people of Muhammad?’ The answer came in the affirmative. Abu Sufyan and his men were taken to the court of Heraclius who had already received a letter from the Prophet inviting him to accept Islam.
That letter to Heraclius was carried by Duhayyah ibn Khalifah al-Kalbi, a famous Meccan businessman who had already accepted Islam, and it read as follows: In the name of Allah, the most Beneficent, the most Merciful.
From Muhammad, the slave and Messenger of Allah, to Heraclius, the emperor of Rome. Peace be on him who follows the guidance. After this, I invite you to accept Islam. Accept Islam and you will prosper and Allah will give you double rewards. But if you refuse, the sin of your people also will fall on your shoulders. O People of the Book! Come to a word common between us and you: that we shall not worship anything save Allah, and that we shall not associate anything with Him, nor shall some of us take others for lords besides Allah. But if they turn back, then say: Bear witness that we are Muslims.
Duhayyah has said, “As soon as I delivered the Prophet's letter to (emperor) Heraclius, he ordered the patriarch of his empire to be brought to him. When the patriarch came, Heraclius showed him the Prophet's letter. Having read it, the patriarch said, ‘This is the Prophet whose advent we have been expecting! Jesus son of Mary conveyed to us the glad tidings about him.'
Then the patriarch added saying, ‘As far as I am concerned, I believe in him, and I follow him.' Heraclius said, ‘As far as I am concerned, if I do the same, I shall lose my kingdom.' After a while, Heraclius said, ‘Find me some of his own people who are here so that I may ask them about him.' Abu Sufyan and a group of businessmen from Quraish happened to be in Greater Syria at the time. Those businessmen were brought to Heraclius who said to them, ‘Let the one closest in kinship to him come forward to talk to me.' Abu Sufyan came forward.’
Let us stop here for a minute to introduce the kind reader to this great man, Duhayyah ibn Khalifah al-Kalbi.
Duhayyah was a successful businessman. Before accepting Islam, he came one day, as usual, to Medina's bazaar (near the Prophet's mosque) and beat his drum to announce his arrival and the presence of his merchandise for prospective buyers as was the custom in those days. Soon a large number of people surrounded him. He asked them where they had been and was told that they were at the mosque praying with Muhammad, the Messenger of God. “Do you mean to tell me that you came here to buy something, leaving your Prophet behind?!’
When their answer came in the affirmative, Duhayyah rebuked them thus:, “Fie upon you, folks! Do you have any sense of shame at all for doing that?! Get away from me! I am not selling you a thing.’ He immediately packed his wares and left the bazar. The Almighty appreciated what Duhayyah had done out of respect for His Prophet notwithstanding the fact that Duhyyah had not yet believed in Muhammad and in his message. Duhayyah later accepted Islam. As a token of appreciation from the Almighty to him, the arach-angel of revelation, Gabriel, used to go to Prophet Muhammad looking like Duhayyah who was one of the most handsome businessmen in Mecca and Medina. Here is a proof testifying to Gabriel impersonating Duhayyah: Ibn ‘Abbas narrates in a consecutively narrated tradition transmitted by a chain of reliable narrators saying that the Messenger of Allah used to love to see Ali as the first person to visit him every day in the late morning. The Prophet was in his house's courtyard one morning, resting his head on the lap of Duhayyah ibn Khalifah al-Kalbi, napping, when Ali arrived. He addressed Duhayyah thus, ‘Assalamo Alaik! How is the Messenger of Allah doing?’ Duhayyah said, “Very well, O Brother of the Messenger of Allah!’
Ali said, “May Allah reward you on our behalf, we Ahl al-Bayt, with good rewards.’ Duhayyah responded to this by saying, “I love you, and I would like to express a compliment to you as a gift from me to you. Here it is: You are the Commander of the Faithful (Ameerul-Mo'mineen), leader of the victorious hosts, and the master of all the descendants of Adam on the Day of Judgment with the exception of the prophets and the messengers. The standard of praise shall be in your hand on the Day of Judgment.
You shall be escorted, you and your supporters (Shi’as), in the company of Muhammad and his party to the Gardens. Successful is he who accepts you as his wali; a disappointed loser is he who abandons you. Due to Muhammad's love for you did they love you, hating whatever Muhammad hated. Those who hate you shall never receive any intercession from Muhammad. Those who love you are the choicest of Allah's people.’ Then Duhayyah tried to adjust the Prophet's head in his lap when the Prophet woke up and inquired about that whispering. Ali told the Prophet that he was talking with Duhayyah, whereupon the Prophet said, “That was not Duhayyah! That was Gabriel! Gabriel called you by the name whereby Allah, the most Ealted One, calls you, and it is He Who cast love for you in the hearts of the mu'mins, casting fear of you in the hearts of the kafirs,’ As we read on pp. 267-268 of Vol. 18 of al-Majlisi's Bihar al-Anwar.
Now let us return to what went on between Heraclius and Abu Sufyan.
The conversation that took place between Heraclius and Abu Sufyan is preserved in the books of traditions thus:
Heraclius: Is the family of the person claiming prophethood a noble one?
Abu Sufyan: It is a noble family.
Heraclius: Has anyone else in this family claimed prophethood?
Abu Sufyan: No.
Heraclius: Has there been any king in this family?
Abu Sufyan: No.
Heraclius: Are the people who have accepted this religion weak or influential?
Abu Sufyan: They are weak people.
Heraclius: Are his followers increasing in number or decreasing?
Abu Sufyan: Their number is on the increase.
Heraclius: Have you ever known him to tell lies?
Abu Sufyan: No.
Heraclius: Does he ever commit a breach of any pact?
Abu Sufyan: He has not done it so far, but we would like to see if he keeps up a new peace treaty that we have recently negotiated with him.
Heraclius: Have you ever fought him?
Abu Sufyan: Yes.
Heraclius: What was the result?
Abu Sufyan: Sometimes we won and sometimes he.
Heraclius: What does he teach?
Abu Sufyan: He bids people to worship one God and not to associate any partners with Him, to offer prayers, to be truthful and chaste, and to bestow alms.
Heraclius then summed up the conversation thus: You say that this man belongs to a noble family. Prophets always come from noble families. You say that no one else in the family ever before claimed prophethood. Had it been so, I would have thought that he was influenced by family traditions. You say that none of his predecessors was a king. Had it been so, I would have thought that he was aspiring to attain kingship. You admit that he never tells lies.
A person who does not tell a lie to a man cannot tell a lie about God. You say that poor people are the adherents of his creed. The first followers of prophets always come from this class. You say that his religion is expanding. This is characteristic of a true religion. You say that he does not deceive. Prophets do not deceive anyone. You say that he bids you to offer prayers and to observe purity and chastity. If all this is true, his realm will come right up to my domain. I had thought that a prophet might be coming, but I did not think that he would be born in Arabia. If I could go there, I would have paid homage to him.
Abu Sufyan used to say that he had to give true answers to the emperor, as he was afraid of being contradicted by one or more caravan companion if he gave any false reply.
Heraclius wanted to know more about Muhammad's religion. He, therefore, sent a man from the tribe of Ghassan with these instructions: “Report to me three observations: 1) see on what he sits; 2) see who sits on his right side; and 3) if possible, try to find out what his seal says.’ The man came to the Prophet and found him sitting on the ground treating his feet with warm water. Ali was sitting on his right side. “Who is this man?,’ he asked. “Ali, the Prophet's cousin,’ he was told.
He wrote down his observations, forgetting the third instruction. The Messenger, seeing how the man was trying to remember what he had forgotten, instantly said to him, “Come and take a look at what your fellow (Heraclius) had instructed you to try to see,’ showing him his seal. The man returned to Heraclius and reported to him all what he had seen. “This is the one foretold by Jesus son of Mary! He rides the camel; so, you should follow him and believe in him.’ Then he said to his messenger, “Go and invite my brother (to Islam), for he is my partner in the kingdom.’ The messenger went back to report to Heraclius that his brother was not receptive to the idea at all, fearing the loss of his kingdom, as we are told by al-Majlisi on p. 378, Vol. 20, of Bihar al-Anwar.
The letter Muhammad sent to Khosrow II Parviz son of Hormizd IV, the Sasanian Kisra of Persia, was carried by ‘Abdullah ibn Huthafah. It stated the following as recorded by the historian al-Ya’qubi: In the Name of Allah, the most Gracious, the most Merciful
From Muhammad the Messenger of Allah to Khosrow son of Hormizd. Accept Islam, so you will be safe (from Allah's wrath); otherwise, be forewarned of a war from Allah and His Messenger, and peace be with whoever follows the right guidance.
Khosrow Parviz was enraged at the very idea of an “ordinary’ person addressing him, the great Kisra that he was, on terms of equality, and even starting with his own name before that of his; so, he tore the letter to pieces[3]. In his rage, he said, “Who is this person who invites me to accept his religion and starts his letter with his name before mine?!’ As a token of his ridicule, Khosrow Parviz sent the Prophet some of his country's soil. When the Prophet was informed that Khosrow had torn his letter to pieces, he said, “May Allah tear his domain to pieces just as he tore my letter. For sure, his domain shall be torn apart. He sent me soil… For sure, you will come to possess his land.’ And so it was.
Khosrow Parviz, further directed his governor over Yemen Firoz al-Daylami, nicknamed “Abu Mahran,’ who used to be one of the ministers of Sayf ibn Thee Yazun,[4] to arrest the person claiming to be a prophet and to send him to his court. The governor's messengers arrived at Medina and asked the prophet to comply with Kisra's orders on pain of his country's destruction, giving him one night to do so. The Prophet replied, “My God informed me that your lord was killed last night; God sent upon him his son Sheroe[5] after seven hours of the night had passed; so, wait till this news reaches you, ‘ as we read in al-Majlisi's Bihar al-Anwar, Vol. 20, p. 382.
As the reader knows, all the above took place in 628 A.D. In order to verify the accuracy of the date of death of Khosrow Parviz, I consulted the Micropedia of the Encylopedia Britannica III, and I found this exact date: 628 A.D. recorded as the date of death of this Persian Kisra. The reader can see the same for himself on p. 793 of Vol. 5 of the said Encylopedia. Surely Allah and His Messenger always say the truth! Allahu Akbar!
It also gives me pleasure to assure the discreet reader that I went to extremes verifying the dates (Hijri and Gregorian) contained in this book, spending a great deal of time comparing one reference with another, consulting both Arabic and English references so that each and every date is accurate. Only Allah knows the extent and the pain of my frustration whenever I came across so many discrepencies relevant to historical data in print. Having verified all these dates in classic books, I further consulted a computer program for final verification.
The reader can now rely on these dates as much I, the author, can, and surely Allah knows best. All Praise is due to Allah, and only to Allah, Who has enabled me to write this book and other books that I have also written, translated, or edited; I humbly thank Him for it and pray that He accept my endeavour as a mere token of appreciation of all what He has done for me although the favour of writing it is most surely His, not mine. We all are tools in the hands of the Almighty and nothing more. The will of Allah be done.
It is interesting to state here that Prophet Muhammad used a seal for the very first time in this same year after being told that the monarchs ruling the domains beyond Arabia would not honour any letter unless it was sealed.
The Prophet's letter to al-Harith ibn Abu Shimr al-Ghassani, chief of the Ghassan tribe ruling western Syria, was carried by Shuja’ ibn Wahab, who was put to death by al-Harith. The Ghassan tribe was an Arab tribe that inhabited the Western side of the Syrian Desert during the Prophet's time.
This eventually became the cause of a conflict with the Christians (then the dominant power over Syria) which resulted in the Battle of Mu'tah in 629 A.D. and the Expedition of Tabuk in 630 A.D.
The Prophet sent an epistle to al-Munthir ibn Sawa, the then King of Bahrain appointed by the Persian emperor, was delivered by al-’Ala ibn al-Hadrami. It read as follows: In the Name of Allah, the most Beneficent, the most Merciful. From Muhammad, the Messenger of Allah, to al-Munthir son of Sawa: Peace on him. Praise be to Allah besides Whom there is no other god. And I bear witness that there is no god except Allah and that Muhammad is His servant and messenger. And now I remind you of Allah, the Mighty and the Glorious. Whoever receives admonition receives it for his own good, and whoever obeys my envoys and follows their instructions obeys me. Whoever is sincere to them is sincere to me.
My envoys have spoken well of you. I have accepted your intercession on behalf of the people of Bahrain. Leave to the Muslims all they owned before accepting Islam. While I hereby grant indemnity to the wrongdoers, you should also forgive them. You shall not be deposed so long as you conduct yourself well. And whosoever continues following his (religion of) Judaism shall be liable to pay the jizya (protection tax).
The letter sent earlier to Negus, the king of Abyssinia, which was carried by ‘Amr ibn Umayyah al-Damri, stated the following: In the Name of Allah, the most Beneficent, the most Merciful. From Muhammad, the Messenger of Allah, to Negus, the king of Abyssinia: Peace on him who follows the path of Guidance. Praise to Allah besides Whom there is no other god, the Sovereign, the Holy One, the Preserver of Peace, the Keeper of the Faithful, the Guardian. I bear witness that Jesus son of Mary is indeed a spirit of God and His word which He conveyed unto the chaste Virgin Mary. He created Jesus through His word just as he created Adam with His hands. And now I call you to Allah Who is One and has no partner, and to friendship in His obedience. Follow me and believe in what has been revealed to me, for I am the Messenger of Allah. I invite you and your people to Allah, the Mighty, the Glorious. I have conveyed the message, and it is up to you to accept it. Once again, peace on whoever follows the path of guidance.
Another epistle sent to Muqawqis, the then Roman Viceroy over Egypt, was carried by Hatib ibn Balta’ah and it said: In the Name of Allah, the most Beneficent, the most Merciful. From Muhammad, the servant and Messenger of Allah, to Muqawqis, Chief of the Copts: Peace on him who follows the path of guidance. I invite you to accept the message of Islam. Accept it and you shall prosper. But if you turn away, the sins (of misleading by your example) of the Copts shall fall upon you. O people of the Book! Come to a word common between us and you: that we shall worship none but Allah and that we shall ascribe no partners to Him and that none of us shall regard anyone as lord besides God. And if they turn away, then say: Bear witness that we are Muslims.
According to a number of books of history, the Prophet also sent Saleet ibn ‘Amr al-’Amiri with two of his letters to both kings ruling Yemen then: Thumal ibn Athal and Hawthah ibn Ali who belonged to the tribe of Banu Haneef. I very much wished to research the text of those letters and the response to them, but I could not do so due to the deadline which I had to meet before sending this book's manuscript to the press. I seek forgiveness of Allah, of His Prophet, and of the kind reader. Deadlines are one of the inconveniences writers have to tolerate.

Notes:
[1] He was the late Sassanian king of Persia under whom the empire achieved its greatest expansion. He ascended the throne in 590 A.D. following the assassination of his father Hormizd IV and remained the emperor till his death in 628 A.D. His wife was an Armenian Christian named Shirin. He received Prophet Muhammed's letter shortly before his death.
[2] al-Majlisi, Bihar al-Anwar, Vol. 20, p. 384.
[3] Sayf ibn Thee Yazun (or Thee Yazin) (d. 574 A.D.) was one of Himyar's kings who kicked the Ethiopians out of Yemen assisted by the just Sasanian Persian emperor Kisra Anushirwan, better known as Khosrow I (d. 579 A.D.). Sayf is praised in a poem by Umayyah ibn Abu al-Salt.
[4] Sayf ibn Thee Yazun (or Thee Yazin) (d. 574 A.D.) was one of Himyar's kings who kicked the Ethiopians out of Yemen assisted by the just Sasanian Persian emperor Kisra Anushirwan, better known as Khosrow I (d. 579 A.D.). Sayf is praised in a poem by Umayyah ibn Abu al-Salt.
[5] Sheroe is also known in Persian history as Qobad II. He was Khosrow's eldest son. He assassinated his father in Khurasan.