The following is from Michael Hart's book and lists Prophet Muhammad as the most influential man in History. A Citadel Press Book, published by Carol Publishing Group
Ranking of the twenty from the list of 100:
Shih Huang Ti
MUHAMMAD, No. 1
The 100, a Ranking of the Most Influential Persons in History
by Michael H. Hart
My choice of Muhammad to lead the list of the world's most influential persons may surprise some readers and may be questioned by others, but he was the only man in history who was supremely successful on both the religious and secular levels. Of humble origins, Muhammad founded and promulgated one of the world's great religions, and became an immensely effective political leader. Today, thirteen centuries after his death, his influence is still powerful and pervasive. The majority of the persons in this book had the advantage of being born and raised in centers of civilization, highly cultured or politically pivotal nations. Muhammad, however, was born in the year 570, in the city of Mecca, in southern Arabia, at that time a backward area of the world, far from the centers of trade, art, and learning. Orphaned at age six, he was reared in modest surroundings. Islamic tradition tells us that he was illiterate. His economic position improved when, at age twenty-five, he married a wealthy widow. Nevertheless, as he approached forty, there was little outward indication that he was a remarkable person. Most Arabs at that time were pagans, who believed in many gods. There were, however, in Mecca, a small number of Jews and Christians; it was from them no doubt that Muhammad first learned of a single, omnipotent God who ruled the entire universe. When he was forty years old, Muhammad became convinced that this one true God (Allah) was speaking to him, and had chosen him to spread the true faith. For three years, Muhammad preached only to close friends and associates. Then, about 613, he began preaching in public. As he slowly gained converts, the Meccan authorities came to consider him a dangerous nuisance. In 622, fearing for his safety, Muhammad fled to Medina (a city some 200 miles north of Mecca), where he had been offered a position of considerable political power. This flight, called the Hegira, was the turning point of the Prophet's life. In Mecca, he had had few followers. In Medina, he had many more, and he soon acquired an influence that made him a virtual dictator. During the next few years, while Muhammad's following grew rapidly, a series of battles were fought between Medina and Mecca. This was ended in 630 with Muhammad's triumphant return to Mecca as conqueror. The remaining two and one-half years of his life witnessed the rapid conversion of the Arab tribes to the new religion.