It was the martyrdom of Hazrat Usman. It was the first spark and first successful attempt which was put into the Muslim unity by the hypocrites and enemies of Islam.
It was the wars between Hazrat Ali and Hazrat Ayesha and Amir Muawaiya. It was the first drop of oil which was put to the spark to blow up into flame.
It was the martyrdom of Hazrat Imam Hussain. It was the last and successful attempt of hypocrites to make that fire an encircling flame which ruined for ever the unity of Muslims.
It was the downfall of Muslims State in Spain. Though it took place due to the weakness of Muslim themselves but Christian States and King Ferdinand also played their part. The downfall of Spain gave a rude shock to Muslim prestige which lost its awe and image in the eye of Christian world.
Fifth cause was Crusades. These wars beginning in 1096 continued for more or less tow hundred years. Though the result of wars was against the Christian, that, Jerusalem remained with Muslims and during the end of the Crusades the Muslims snatched away from Christians those parts of Syria which remained with them till then, but from psychological point of view its evil effects to Muslims and benefit to Christians could not be had in any other way. Muslims being free from Christians engaged themselves in internecine wars. The Christians exploited the situation in the form of their unity by forgetting their religious renaissance which paved the way for their material prosperity and growth. Over and above this they learnt the technique of making better war material and their use, for example, new methods of encircling the enemy; use of cannons; exploding mines which they learnt from Muslims during the Crusade and the experience they got through crusades and travel added to their wealth of information. As trade follows wars, these people went to distant lands which in the long run brought them face to face with eastern learning, discovery of America and conquest of foreign lands and modern prosperity.
It was the discovery of America. At the time America was discovered, Turkey and other Muslims States were so much superior to European nations that they could easily capture America if they wished. If this would have taken place, the map of the world would have been different. But the Muslim rulers of the period were so much engrossed in the life of ease and luxury and internecine wars that they could hardly think about it. Neither they remembered the order of Allah nor the Holy Prophet to travel in the world and gain learning and sustenance and spread Islamic teachings among the depressed class of people. Due to negligence of Muslims European nations amassed wealth from America and in its pursuit they gained enough experience and knowledge and the land of America gave birth to a new nation which is shining on the firmament of culture and prosperity.
Vasco De Gama after going round the continent of Africa found out the sea route of India and Far East which paved the way for direct trade between Europe and countries of the East. Before this the traders carried their entire business through the trade route of Syria, Palestine and Egypt. As the trade route changed the Arab countries were bereft of the trade prosperity which was the cause of their wealth and treasure.
It was the appearance of British and French and the downfall of the Mughal Empire. This was the time when Muslims kings and nobles were leading a life of pomp and pleasure and luxury and were busy in internecine wars. Muslims traders had become bankrupt. The entire learning of Muslim divines was confined to their religious knowledge, that is, commentary and explanations and Sunnah and Islamic Jurisprudence. They were ignorant of modern science and knowledge and were busy in discussions and charges and counter charges among themselves in order to belittle others. On the other hand among European nations due to wealth and prosperity there was search for new learning and discoveries and the spirit of internal activity has taken it root. Hence, first of all, these European nations, acquired trade facilities from Muslims rulers through flattery and later on, taking advantage of their weakness and carelessness, slowly and gradually, captured their domains and built their own castles over the ruins of their kingdoms.
Both British and French struggled for their supremacy in India but as the British were slyer and deceitful they came out successful. First of all through sheer diplomacy and simplicity, they acquired trade facilities and built their trading centers at different places and for their protection kept their troops to guard them. After this with subtle diplomacy they engaged Muslim States again Hindu States and received their share from the victorious states there by making their position strong and powerful. Now it became ready to destroy the Mughal Empire. For this also it applied diplomacy rather than war materials by bribing Nawabs and Salars and making them rebellious of the ruling kings so much so that they were confined to Red Fort only. In 1857 it also came to an end the last emperor of the Mughal dynasty, Bahadur Shah, was deported to Rangoon and the British became undisputed ruler of India. How the British behaved with Muslims and how they ruined the Muslims through diplomacy and treachery can be known through the perusal of history.
It was the destruction of the Turkish Empire. The British applied different methods to destroy Turkey. On one side it separated Egypt from Turkey through diplomacy and on the other formed an alliance of Russians, French and other European nations and excited the people South of Danube from east to west who were under Turkey to rebel again Turkey and declared them independent. When Turkey became weak the British gave it its last blow during the First World War by bribing the disloyal Arab Sheikhs who rebelled against Turkey and became independent. The British tried to wipe out Turkey from the map of the world. But Allah sent to Turkey a warrior of courage and faith “Mustafa Kamal” who saved Turkey from death and destruction. Turkey of today owes its existence due to the sweat and toil of this valiant soldier.
The greatest harm brought by British propaganda and influence was the elimination of Unity of Islamic brotherhood from the mind of Muslims and crating the national feeling and spirit among them so much so that even Muslims divines, ignorant of world situation, started saying that nations are not created by religion but by national states. And now Muslims of one state consider Muslims of another state unrelated to him and strangers.