One of the great religion, the ISLAM emerged as a great political force within a century of it's birth.  Prophet Mohammad founded Islam in 571 AD, in Saudi Arabia.  A poverty stricken orphan took off as a shepherd and later served a wealthy widow Khadija who was almost double his age.  Khadija was fascinated by the young charming loyal Mohammed and married him.  Mohammed was about 25 years old when he got married.  He took care of Kadija's trade caravans for the next fourty years which had belonged to him by then.

Qureshis were idol worshippers and had their main shrine (Kaba) at Mecca.  Mohammed's view towards idol as a useless object, made him to preach a simple set of moral codes to his people to overcome their superstitions and in turn to lead them to salvation.  Khadija became the first follower of his newly founded religion and then the others.  This drew more attacks from the idol worshippers and Mohammed was compelled to flee in 622 AD to Yasrile, later called Madina.  The event Hijrat (Migration) marks the beginning of the muslem era called Hijri.  In Madina, Mohammed spent a good deal of his time  preaching his moral code, and the number of his followers continued to grow amidst of serious opposition by idol worshippers. The prophet died in 632 AD.

Caliphs were the religious heads and political leaders too.  Under Caliph, muslim reached great heights of glory.  Missionaries and soldiers carried out the task of spreading Islam with sword and pen to far away kingdoms.  Eventually Islam entered Persia and Rome too.  Then in the eigth century they conquered Syria, Palestine, Egypt, Spain and Africa too.

Arabs were well aware of  India's immense wealth as they learned from the interaction due to trade.  Having been attracted by this, they frequently organized plundering expeditions looting temple and Kings.  It was in 711 AD, the boats carrying gift in the form of gold and gems from Ceylon was looted by sea pirates near Sindh coast Debal.   Raja Dahib of Sindh was persued by Caliph Walid and Al-Hjaj to restore his lost property.  The innocent Raja dahib denied and faced Al-Walid and his army whom Caliph sent to confront.  But Al-Walid was defeated by Raja Dahib.  To further retaliate, Mohammad bin Qasim, the son-in-law of  Al Walid was appointed to battle with Raja Dahib.  Al Walid's army was much powerful this time, and they defeated Raja Dahib.  Raja Dahib was killed in the battle field and his two daughters were sent to Caliph by Qasim as presents.

On one side, Mohammad bin Qasim penetrated the whole of Sindh till lower Panjab, and on the other side Caliphate of Ommayad was briefed by two daughters of Raja Dahib that Mohammad bin Qasim had already dishonoured them. This annoyed the Khalipha who ordered that Mohammad bin Qasim to be sewn in the ox hide and sent immediately.  Thus Mohammad bin Qasim breathed his last because of Suryadevi and Parimaladevi's conspiracy.  Arabs thus started ruling Sindh.  As the time passed, they realised that the land of Sindh was infertile and too expensive to meet the army expenses and the fact that it is far from their main shrine.  They slowly lost their interest in Sindh and let Sindh people to decide their own future and freed from their clutches.  In consequence of the failure to hold Sindh, India remained  free from Muslim aggression for the next three hundred years.