​Before Mohammad died, he and his Muslim followers had conquered and subjugated the entire Arabian Peninsula.  For the next approximately 300 years, Islam expanded at an astonishing rate in all directions.  The people that were conquered were forced to submit to Islam and many were forced to convert, either under the threat of death or under the certainty that they would live as subjugated people unless they converted.  People who spoke the words to accept Islam immediately entitled themselves to equality of treatment.  Although there is evidence suggesting that Arabs often maintained a certain superior status, the subjugated people who converted achieved a much better status than those who refused to convert.  Poly-theists and pagans were particularly ill-treated.  Jews and Christians, as monotheists, received somewhat better treatment but they still had to submit to Islam and could never be assured of freedom to practice their own religion in freedom and safety.  

The history of Islamic expansion out of the Arabian Peninsula is often one of constant but gradual encroachment into the lands bordering Islamic-controlled nations.   Much like what is happening today!  Islam also became a tool and rallying point that war-lords and conquerors used to justify their conquests and to encourage their followers to risk and embrace death for the glory of Islam (and, of course, the success of the leader).  In Islam, there is one sure way for a person to achieve salvation;  martyrdom.  As defined by Islam, martyrdom is death while fighting non-Muslims or being killed by non-Muslims.  Devout Islamic extremists often claim to love death! ​.

Islamic expansion into Asia and India was extremely violent and the death-toll was horrific – although the death tolls in all the Islamic conquests was high.  The Islamic expansion to the north and west initially confronted the Christian Byzantine Empire which was the eastern remnant of the collapsing Roman empire.  This obstacle slowed but did not stop Islamic expansion into Eastern Europe.  Islam swept through North Africa and has remained dominant throughout this region until the present time, although it had been predominantly Christian for nearly seven centuries before the introduction of Islam.   Islam crossed into Spain and for about nine hundred years was dominant on the Iberian Peninsula and even encroached into southern France.  Spain was only returned completely to Christian control in the early years of the 17th century.   

By the end of the 11th century, Islam ruled in four-fifths of the territory that had been controlled by Christians prior to the attack by Islam.   Europe remained mostly Christian and was somewhat protected from the Islamic onslaught by the Byzantine Empire and by the Mediterranean Sea.  But Byzantium was weakening as a result of the constant warfare with Islam as well as due to decay and corruption from within.  In the later years of the 12th Century Pope Urban of the Roman Catholic Church called on Christians everywhere to unite to confront the aggression of Islam and to re-take the Holy Land from the Muslims who had been increasingly interfering with pilgrimage to the Holy Land. 

This resulted in a series of Crusades that checked the expansion of Islam into Europe and resulted, for a number of years, in the formation of Christian kingdoms in the middle east.  To this day the Crusaders are particularly reviled in Islam which claims that the Crusaders were especially aggressive, bloodthirsty and barbaric.  It is true that some atrocities occurred perpetrated by Crusaders.  Warfare inevitably loosens the constraints against evil actions in those people who are attracted to evil.  This is true regardless of the virtues of the cause for which these people are fighting.  But it should also be noted that the Crusaders did nothing that Islamic armies had not done repeatedly over the previous 3 centuries.   While the actions of some Crusaders were reprehensible, the Islamic response to their actions shows another common facet of today’s Islamic leadership which often and loudly condemns actions by non-Muslims that are actually very similar to the actions of Islamists.  What is OK for Islamists is often considered not to be OK for opponents of Islam!

It should be noted that during and after the Crusades, the Muslim population of the Holy Land was never forced by the Crusaders to convert to Christianity.

The Crusades were weakened in the later years due to a wide variety of factors.  For some of the Crusaders, self-interest overcame their devotion to the cause of Christianity.  The Black Death swept through Europe and put immense pressure on the nations that had supported the Crusades.  The Crusaders were not used to the climate of the Middle East and were subject to illness and disease as a result.  Ultimately the Europeans were driven out of the Middle East, but the threat to Europe was reduced for a number of centuries and has only been revived in recent years. 

It should be noted that the Crusades were not aimed to retake all lands conquered by Islam.  They concentrated on the Holy Land.  Some Crusaders were guilty of atrocities but it should also be remembered that the Crusades, themselves, were the result of and a reaction to 300 years of Islamic aggression. 

The Islamic apologists that condemn the Crusaders and blame them for the actions of radical Islamists today are simply misguided, mistaken or dishonest.  As pointed out previously, the root of the antagonism between Islam and non-Islamic countries lies in the actions and instructions of Mohammad in the 7th century, not in the Crusades of three centuries later.

The Crusaders did not halt Islamic expansion into Asia, Africa and India.  The Ottoman Empire expanded into all these areas in that same period of time.  Europeans and North Americans grow up hearing very little about the Ottoman Empire.  However, this Empire, which was centered in Turkey, was one of the largest empires in the history of the world and was also one of the longer-lasting empires in history (over 400 years).  It was disbanded and broken up in the aftermath of World War One.   The post WWI map of the middle east was arbitrarily created from the corpse of the Ottoman Empire.  The current national borders do not necessarily outline areas of shared national interest, common ethnicity or religious consensus.  This fact in itself has lead to a lot of the discord and warfare in the region.  And most of this strife and warfare has been between different ethnicities and factions within the “House of Peace” of Islam itself (See the page4 on "Muslim Relations With Non-Muslims" for a discussion of the Islamic concept of Dar-as-Salaam).     
In its time, the Ottoman Empire was considered by many Muslims to be the legitimate political ruling body of Islam – what was called the Caliphate.  Allegiance to the Caliphate is considered by many Muslims to be more important than allegiance to the nation in which they live.  Nationalism as it is known in non-Islamic countries is not as prevalent in Islam.  On the other hand, support for the expansion of Islam until it dominates the entire world is a very common attitude with Muslims. A critical point to be made in this section is that to most Muslims, nationalism as we know it in the West is not a strong motive force.  However, support for and allegiance to the “Caliphate” is strong among most Islamic sects.  For example, ISIS claims to be the legitimate caliphate.  This explains the amount of support that this organization receives from Muslims who live far removed from its area of control.

Some contemporary scholars suggest that many of the more objectionable teachings of Islam did not come from Mohammad at all but were rather authored by subsequent leaders of Islam who created these instructions to legitimize and facilitate their conquests and their regimes. It seems that the teachings of Islam are perfectly designed to create a following of violent and dedicated warriors who will gladly accept death to further the designs of their leader – as long as that leader professes to believe in Allah.  It is sometimes even suggested that Mohammad was a made-up personality who never actually existed.  While either of these suggestions are possible, we find them both unlikely.  In fact, they are not particularly relevant to this discussion.  We maintain that, regardless whether Mohammad or another person or people created this cult, it does not originate with the Creator God and it is based in evil.

- The Early Expansion of Islam