Who is the Messenger of Islam?

Letter Muhammad in Arabic written on a door
He is Abul-Qasim, Muhammad, the son of Abdullah, the son of Abdul-Muttalib, the son of Hashim. He belonged to the Arab tribe of Quraish whose ancestry traces back to 'Adnaan, one of the children of Ishmael, the Prophet of Allah. Ishmael was the son of Abraham, who was the messenger of Allah, may Allah praise him.
He was born in the year 571 C.E. in the honored city of Makkah. Makkah was the religious center of the Arabian Peninsula, as it housed the Honored Kabah, which was built by Abraham and his son, Ishmael.
Even before he received revelation, he was known amongst his people as 'The Trustworthy', and they would entrust him with their possessions when they intended to go on a journey. He was also known as 'The Truthful" due to what they knew of him from truthfulness. He never lied or acted treacherously. He always desired good for others.
He received his first revelation at the age of forty and informed his wife, Khadeejah, may Allah be pleased with her, apprehensively:
"Indeed I fear for myself." Khadeejah replied, "No, by Allah! Allah will never humiliate you. Indeed you maintain ties of kinship, you bear the problems of others, you give wealth to those who do not have it, you honor and feed your guests, and you give support in times of true calamity." (Bukhari)
He remained in Makkah for thirteen years thereafter, calling people to believe in the Oneness of Allah. He then migrated to the city of Medina and called its inhabitants to Islam, which they accepted. There, Allah revealed to him the remaining legislations of the religion.
He returned and conquered Makkah eight years after his migration, and died at the age of 63 after Allah revealed to him the entire Quran. All the legislations of the religion were perfected and completed and majority of the Arab nation accepted Islam.
What Do They Say About Muhammad?
George Bernard Shaw in The Genuine Islam said:
"I have always held the religion of Muhammad in high estimation because of its wonderful vitality. It is the only religion which appears to possess that assimilating capability to the changing phases of existence which make itself appeal to every age - I have prophesized about the faith of Muhammad that it would be acceptable tomorrow as it is beginning to be acceptable to the Europe of today. Medieval ecclesiastics, either through ignorance or bigotry, painted Mohammedanism in the darkest colors. They were, in fact, trained to hate both the man Muhammad and his religion. To them, Muhammad was an anti-Christ. I have studied him, the wonderful man, and in my opinion, far from being an anti-Christ, he must be called the Savior of humanity."2
Annie Besant (3) in The Life and Teachings of Mohammad, said:
It is impossible for anyone who studies the life and character of the great Prophet of Arabia, who knew how he taught and how he lived, to feel anything but reverence for the mighty Prophet, one of the great messengers of the Supreme. And although in what I put to you I shall say many things which may be familiar to many, yet I myself feel, whenever I reread them, a new way of admiration, a new sense of reverence for that mighty Arabian teacher.