In the ten years between the Hijra and his death (622 AD to 632 AD), Muhammad sowed the seeds of a theocratic Arab nation. This was increasingly accepted by a greater number of Arabs, overcoming tribal barriers towards the emergence of social, political and religious unity. With the death of the Prophet, the Caliph, an Arabic term meaning "successor", took charge of the community. From the outset, the succession of the Prophet and the legitimacy of the Caliph were the subject of dissent, leading to numerous divisions throughout the history of Islam.

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          The first Caliph, Abu Bekr, unified the Arabian Peninsula less than a year after the Prophet's death. An army of believers was then formed which soon surpassed the borders of northern Arabia, showing its strength against the territories dominated by Persia and the Byzantine Empire. The entry of Muslims into territories dominated by Byzantium was partly facilitated by the religious quarrels of the Monophysites. In Egypt, too, the arrival of the Arabs was facilitated by deep dissension. With the conquest of Egypt, the first phase of Muslim expansion came to an end, followed by the maritime conquests that put an end to Byzantine supremacy in the Mediterranean.

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​           The last Caliph of this initial period, ‘Ali, the Prophet’s son-in-law, came under great political pressure and transferred the capital to Kufa, in Iraq. During this period, the unity of the Muslim world and Arab supremacy underwent great transformations and internal divisions.

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