The Abbasids are the descendents of Abbass Ibn Abdel Muttalib, one of the uncles of Prophet Mohammad. The Abbasids is the second dynasty in the Arab Islamic history and had based their claim to be the rightful heirs of the Caliphate by the virtue of their descent. They are considered one of two clans of the Hashemite family while the other branch is the Alawis, or the followers of Ali Ibn Abi Taleb.
The Abbasids used their descent in their struggle against the Umayyads as they called for a Caliph who belongs to the Prophet's family, the Hashemite. By this the Abbasids guaranteed the support of the Alawis. They also managed to gain the support of the Persians who were the main core of their struggle for power. However after the Abbasids had formed their new dynasty they turned their back to the Alawis and tortured many of their leaders.
The Abbasids established the round city, Baghdad, to be their capital away from Damascus that has witnessed Umayyad's influence. The first Abbasid era (132-232 Hijri) is considered the most prosperous time for this dynasty in many fields including culture, science, politics and military. Also a number of the Caliphs of this age are well known in history, among which are Haroun Arrashid and Al-Ma'mun.
During the second Abbasid era the dynasty became weaker and many quasi independent states were established on its margin, both in the east and the west. The Abbasids still maintained a feeble show of authority, confined to religious matters. Later the Caliphate capital moved to Cairo under the rule of the Mameluks where it stayed until the Ottomans invasion of Egypt.
Egypt was ruled all through the Abbasid era by rulers appointed by the Abbasid Caliph. It is worth mentioning here that the rulers of Egypt during the era of the Rightly-Guided Caliphate and the Umayyads were all Arabs as a part of a broader strategy that depended mainly on Arabs in all political and administrative fields. At that time the supervision upon all political, administrative and military affairs as well as the high ranks in the army were all saved for Arabs and not the natives. However, under the Abbasids, non-Arabs became a part of the ruling class and gradually the Arabs lost their privileges. A number of Egypt's rulers under the Abbasids were non-Arabs, as Anbasa Ibn Is-hak Al-Dhaby was the last Arab ruler under the Abbasids (238-242 Hijri.) The non-Arabs rulers, who did not speak fluent Arabic, no longer led the Friday prayers but used to choose a deputy to act as an Imam.
One can also notice that Egypt's rulers were changed frequently under the Abbasids, that Egypt had witnessed from the beginning of the Abbasid Dynasty until the rise of the Fatimid Dynasty about 82 Walis, some of whom were appointed twice.
The Feudal system in some of the provinces of the Abbasid Dynasty, including Egypt, and the quasi independence of these provinces in the time of weakness of the dynasty, were reasons behind attempts of establishing independent states all over the Abbasid empire among which are the Tulunids and the Ikhshidids.
One of the characteristics of the Abbasid era is the strong coexistence between the Muslims and the Arabs on one hand and the Egyptians on the other because of Al Mu'tasem's decision to dismiss the Arabs from the army and abduct their bonuses, which, accordingly, forced them to mingle with the natives. However, this resolution did not elicit a violent response as some historians mention. The mingle was even older than that and had witnessed a big rise.
By the end of the Abbasid era Egypt started to play a stronger and a more effective role in the scientific and political life. Many scholars in the fields of religion, language, poetry and history were Egyptians and were very well known in Africa and Andalusia. This time is also known by the revival of arts and architecture. Al Fustat had the highest buildings and the major population and the Abbasids built Al Rhodes Nilometer. In addition, a number of trades and industries revived (ex. Shipbuilding and textile industry).