The prevailing aridity in the north and centre of the Arabian Peninsula hindered agricultural development (except in oases) and settlement. The inhabitants or Nizari, known as Bedouins, formed independent nomadic tribes led by a sheikh. In the Hiyaz region, the merchant caravan routes linking India and Europe passed through some oases where cities such as Yatrib (that would later become Medina) and Mecca arose.
The rest of the Arabs, the Yemeni, lived in Southern Arabia, where monsoons originating from the Indian Ocean favoured agriculture and a settled way of life. Some cultures, such as the Minaean and Sabaean Kingdoms, existed here around the 9th Century B.C.
On the contrary, society in the north remained fundamentally tribal and nomadic. These groups frequently fought each other and lacked political organisation.
By the end of the 5th century there was a failed attempt at unifying of the tribes of Central Arabia under the Kingdom of Kinda.
According to Muslim tradition, when Muhammad (570-632 A.D.) was about forty, the Archangel Gabriel visited him and he found out he had been chosen by Allah to be his messenger and preach his word. The revelations he received were written in the Koran.
Until that moment, Arabs had been polytheists. Allah had been the lord of the temple, that is, of the Kaaba in Mecca, but had lost preponderance since the 4th Century.
The rejection of his preaching led Mohammed to flee the pagan or polytheist Mecca, his birthplace, and he emigrated to Medina. This act is named as the «hijra» and signals the start of the Islamic era, in September 622.
Muhammad became the religious and political leader of his followers in Medina and the old tribal organizations were substituted by the community of the faithful (Umma).
There were a number of confrontations between citizens of Medina and Mecca, but the latter always lost. Muhammad’s prestige increased and, after a campaign to expel Jews from Medina, he took control of the city.
In 630, Muhammad’s forces conquered Mecca.
The expansion of Islam continued and before his death in 632, Muhammad had established his rule over most of Arabia.
As Muhammad had no children and did not designate a successor, a political crisis took place which was solved with the election of his father in law, Abu Bakr, as the first Arab Caliph. Bakr was succeeded by Omar (‘Umar), who was murdered in 644.
Osman (Uthman) from the Umayyad clan was Caliph until 656, when he was also assassinated. Ali ibn Abu Talib, or simply Ali, Muhammad’s cousin and son in law, founder of Shiite branch of Islam, then became Caliph.
These four Caliphs began the expansion of Islam. Their main goal was to preach and spread their faith. First they established their rule in Arabia and then conquered Syria, Mesopotamia, Persia, Egypt and Cyrenaica -a region located on the northwestern coast of present day Libya, in Northern Africa. There were also campaigns in Asia Minor, the islands in the Aegean Sea and Armenia.
This dynasty of Caliphs began in 661, with Muawiya I and came to an end in 750. The Umayyad moved the capital of the empire from Medina to Damascus, the present capital of Syria, and were responsible for the Arab Empire reaching its greatest extent.
First they conquered Tripoli, in the northeast of what is now Libya, and Maghreb, a region of Northern Africa which takes in the current countries of Morocco, Tunisia and Algeria. The submission of Northern Africa was achieved between 697 and 707.
In Europe, Tarik’s forces defeated the Visigoths in the Iberian Peninsula and arrived in France, where they were stopped by Charles Martel at the Battle of Poitiers in 732 A.D.
In the east, they established dominion over Persia (present day Iran), Afghanistan and Turkestan (a region in Central Asia that includes what is now Uzbekistan, Kazakhstan, Kyrgyzstan, Turkmenistan and Tajikistan), and in the north they reached the regions of Sindh, Punjab and Ode. With the annexation of these territories, Islam had spread from the western Chinese border to the Atlantic Ocean.
The Umayyads established a true royalty, as the old tribal organization became a centralised monarchy. Breaking away from the tradition of Muhammad’s first successors, each caliph, before dying, named his son as heir. To promote Islamisation, non-Muslim subjects in conquered territories had to pay higher taxes.