In the history of Islam, the 30 years following the death of the Prophet is called the Period of Four Caliphs. The Council elected the Prophet’s father-in-law, Abu Bakr, as the first Caliph (632-634). He had been the Prophet’s companion on his flight to Medina and had been appointed to lead prayer in the mosque in place of Mohammed. In the two years before his death, Abu Bakr had regained the alliance of Arab tribes and established crucial Muslim authority over a united Arabia. He was succeeded by Omar (634-644), the second Caliph, who conquered a large part of Syria, Egypt and Mesopotamia. Later Uthman (644-656) was elected and then the fourth Caliph, Ali, served until 661. During the period of the Four Caliphs (632-661) the Near East was conquered from Iran to Egypt. On Ali’s death, power was seized by his rival, Mu’awiya, founder of the Umayyad dynasty (661-750). The Umayyad dynasty enlarged the land held by Islam from Afghanistan in the east to North Africa and Spain in the west. In 750 the last of the Umayyads, dethroned by the Abbasid’s of Baghdad (750-1258), took refuge in Andalucia, and continued in Cordoba until 1090, remaining with the Emirate of the Nasri dynasty in Granada until 1492. The Abbasids were ousted in 1258 by the Mongols, who were themselves converted to Islam towards 1300. They were defeated by the Mameluke Turks, who held control over Egypt. From 1206 until 1526, the Mamelukes, later defeated by the Ottomans, had established their sovereignty in the East, in Delhi, and between 1526 and 1761, North India was governed by the Moghul Empire. Between 1517 and 1924, the power of Islam was represented by the Ottoman Empire, but in 1924, after the Turkish Republic had been founded, the Caliphate was abolished. Today, Islam, a rapidly expanding religion, with almost a quarter of the world population being Muslim, is making its presence felt in every continent. The majority of the populations of the Middle East, North Africa and parts of Asia and Indonesia are Muslim. There are also substantial minorities of Muslims in the West, in the UK, France, Germany and the USA. The Peoples Republic of China also contains a fair number of Muslims.
Jihad, (struggle) means the effort made to achieve a certain objective. It is divided into the Greater Jihad the spiritual battle for self-purification, a fight within oneself against one’s lower passions, such as lust and greed; and the Lesser Jihad, which is a struggle relating to the outside world. This is the act of fighting a sacred war, even putting one’s own life in danger if necessary, in the way of Allah. The cause of such a war must be justifiable and moral, undertaken only as a last resort when all other courses of action have failed.
Early in the history of its development, Islam led the world in rediscovering Greek science and philosophy. By 800, the works of Plato and Aristotle had been translated into Arabic, and Islam adopted Aristotelian philosophy long in advance of the West. Alfarabius (c. 870 – 950), an Arabic-writing philosopher of Turkish origin, followed Plato in politics and Aristotle in logic and physics. His metaphysics combine Aristotelian and Neo-platonic thought. His writings about music are the first ones to show the relation between music and mathematics. The writings of Ibn Sina (Avicenna) (980-1037), some of which are in Persian but most of them in Arabic. They consist of a long philosophical encyclopaedia; nine books on logic, eight books on the natural sciences, including psychology; works on physics and metaphysics, and a famous medical work. These are the most famous of his writings. Later his works were translated into Latin. His Canon of Medicine was studied in European universities for centuries. A student of nature, he examined problems of theology and philosophy and his views attracted much attention during the rise of the Scholastic period. His works were well known at the Chartres School. The Arab philosopher, Ibn Rusht (Averroes) (1126-1198), was at one time the most important thinker for the western world. His works consist largely of explanations and commentaries on the writings of Aristotle. According to him, religion is the metaphoric expression of philosophic truths, and religious faith only another form of intellectual knowledge. He suggests that there is just one universal spirit, which is the embodiment of all the many different varieties of spirits. From this he extrapolates that it is not the soul of the individual but of all humanity that is immortal. Today, a large statue of Ibn Rusht can be seen at the entrance to Barcelona University. These scholars exerted a great influence on scholars in Europe and made prodigious contributions to mathematics, medicine, chemistry, philosophy and astronomy. Named after the great scholar, al-Khwarimi of Khiva, who died in 864 CE, algebra, logarithms and algorithms were all invented by Arab mathematicians. The clue to this is found in words such as algebra and alchemy, the forerunner of chemistry, which start with ‘al’, Arabic for ‘the’. The maps of the world drawn by Arab geographers from the 12th century onwards were remarkably accurate. Al-Idrisi of Morocco, who died in 1166, was one of the world’s most famous cartographers.
In order to perform valid prayers, Muslims must know the direction of the qibla. In former times, this was calculated on the basis of the movements of stars, so the astrolabe was a most important instrument. It was taken from the Greeks and improved by Arab scientists to show, with some degree of accuracy, the positions of the sun and stars at any given time. By the 10th century, in spite of continuous opposition from orthodox Islamic theologists, Islamic astronomy had been developed into a science in its own right. Arab medicine, based on Greek and Indian learning, was quite advanced, although in early Islamic times medicine from a religious viewpoint was regarded with a degree of suspicion, and most physicians were Christian. Many Muslims opposed the study of medicine, regarding it as a divergence from-the-teachings-of-the-Koran.