Arabia, during the time of the Holy Prophet Muhammad (s), was a country without any central authority. It was a country far from the civilised nations of those days.
At the time Prophet Muhammad (s) was spreading Islam; asking people to turn away from worshipping idols to worshipping Allah, the Almighty, the All-Knower, the Master.
The Prophet sent letters of invitation to Kings and Rulers of various countries in the world, inviting them to embrace Islam. Many of the letters were met with a favourable response whilst others were rejected. In many cases, the messengers of the Prophet were badly treated and abused. But the Prophet 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.
Abu Sufyan a leader of the tribe of Quraish and the arch enemy of the Prophet was in Constantinople on a business trip, when the Prophet's letter of invitation reached Hercules, the Byzantine emperor of Eastern Roman Empire. Hercules, at the time was in his court at Constantinople celebrating his victory over the Persians.
Hercules 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 the Prophet. Abu Sufyan with his companions was brought into the court.
The emperor asked Abu Sufyan, "What kind of family does Muhammad belong to?"
"Noble", replied Abu Sufyan
"Has there been a king in his family?" Hercules asked.
"No," said Abu Sufyan
"Are the people who have accepted his religion poor or rich?", Hercules questioned again.
"They are poor", replied Abu Sufyan.
Hercules was now becoming more and more interested and he went on asking questions.
His next question was, "Are his followers on the increase or decrease?"
"Increasing", Abu Sufyan replied shortly.
"Have you known him to tell lies"? asked Hercules.
"No", admitted Abu Sufyan.
"Does he ever go against his convents?", Hercules once again asked.
"Not so far. But we have to see whether he carries out the new agreement made between us and him", Abu Sufyan answered lengthily for a change.
"Have you ever fought him in wars?" Hercules questioned.
"Yes", answered Abu Sufyan
"What has been the result?" Hercules asked, getting more and more interested.
"Sometimes we have won, sometimes he", replied Abu Sufyan.
"What does he teach?" asked Hercules
"Worship One God, join no partners with Him, carry out your prayers, be chaste, speak the truth and keep union with your relatives", answered Abu Sufyan, even surprised at his own answer as it sounded like he was preaching Islam.
Hercules, on hearing this testimony, Hercules stood up and said,"I fully realize that Prophets come from noble families; he does not affect any previous example of Prophethood Since none of his ancestors was a monarch, we cannot then allege that he is a man trying to reclaim his father’s monarchy. So long as he does not tell lies to people, he is for the more reason, immune to telling lies as regards Allâh. Concerning his followers being those deemed weak with numbers ever growing, it is something that goes in agreement with questions of Faith until this latter assumes its full dimensions geographically and demographically. I have understood that no instance of apostasy has as yet appeared among his followers, and this points to the bliss of Faith that finds its abode in the human heart. Betrayal, as I see, is alien to him because real Prophets hold betrayal in abhorrence. Bidding worship of Allâh with no associates, observance of prayer, honesty and abstinence and prohibition of paganism are traits bound to subject to him all my possessions. I have already known that a Prophet must arise but it has never occurred to me that he will be an Arab from among you. If I was sure I would be faithful to him, I might hope to meet him, and if I were with him, I would wash his feet."
Hercules, on hearing this testimony, Hercules stood up and said,"I fully realize that Prophets come from noble families; he does not affect any previous example of Prophethood Since none of his ancestors was a monarch, we cannot then allege that he is a man trying to reclaim his father’s monarchy. So long as he does not tell lies to people, he is for the more reason, immune to telling lies as regards Allâh. Concerning his followers being those deemed weak with numbers ever growing, it is something that goes in agreement with questions of Faith until this latter assumes its full dimensions geographically and demographically. I have understood that no instance of apostasy has as yet appeared among his followers, and this points to the bliss of Faith that finds its abode in the human heart. Betrayal, as I see, is alien to him because real Prophets hold betrayal in abhorrence. Bidding worship of Allâh with no associates, observance of prayer, honesty and abstinence and prohibition of paganism are traits bound to subject to him all my possessions. I have already known that a Prophet must arise but it has never occurred to me that he will be an Arab from among you. If I was sure I would be faithful to him, I might hope to meet him, and if I were with him, I would wash his feet."
This was the way in which the Prophet spread Islam. He impressed them by his truthfulness, honesty, noble character and dedication in the service of Allah. He 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. He fought only in defence, and only when the enemies waged war on him.