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,