Was Islam spread by the sword?

Many non-Muslims, when they think about Islam, picture religious fanatics on camels with a sword in one hand and a Qur'an in the other. This myth, which was made popular in Europe during the Crusades, is totally baseless. First of all, the Holy Qur'an clearly says "Let there be no compulsion in religion".

In addition to this, Islam teaches that a person's faith must be pure and sincere, so it is certainly not something that can be forced on someone. In debunking the myth that Islam was "spread by the sword", the (non-Muslim) historian De Lacy O' Leary wrote: "History makes it clear, however, that the legend of fanatical Muslims sweeping through the world and forcing Islam at the point of the sword upon conquered races is one of the most fantastically absurd myths that historians have ever accepted." (Islam at the Crossroads, London, 1923, p. 8.). It should also be known that Muslims ruled Spain for roughly 800 years. During this time, and up to when they were finally forced out, the non-Muslims there were alive and flourishing. Additionally, Christian and Jewish minorities have survived in the Muslim lands of the Middle East for centuries. Countries such as Egypt, Morocco, Palestine, Lebanon, Syria and Jordan all have Christian and/or Jewish populations. If Islam taught that all people are supposed to be killed or forced to become Muslims, how did all of these non-Muslims survive for so long in the middle of the Islamic Empire?

Additionally, if one considers the small number of Muslims who initially spread Islam from Spain and Morocco in the West to India and China in the East, one would realize that they were far too few to force people to be members of a religion against their will. Additionally, the great empire and civilization established by the Muslims had great staying power -- its citizens were proud to be part of it. The spread of Islam stands in contrast to the actions of the followers of Christianity, who since the time of the Emperor Constantine have made liberal use of the sword - often basing their conduct on Biblical verses. This was especially true of the colonization of South America and Africa, where native peoples were systematically wiped-out or forced to convert. It is also interesting to note that when the Mongols invaded and conquered large portions of the Islamic Empire, instead of destroying the religion, they adopted it. This is a unique occurrence in history - the conquerors adopting the religion of the conquered! Since they were the victors, they certainly could not have been forced to become Muslims! Ask any of the over 1.8 billion Muslims alive in the world today whether they were forced! The largest Muslim country in the world today is Indonesia --- and there were never any battles fought there! So where was the sword? How could someone be forced to adhere to a spiritually rewarding and demanding religion like Islam?
taken from http://www.islamicweb.com/begin/myth8.htm