The Hashemites.

How the modern State of "Jordan" and the Middle East came into being.

The Hashemite family had ruled the city of Mecca in Hejaz, Arabia from 900s CE. The whole region eventually came under the rulership of the Ottoman Turks.
The Ottoman Turks at first allowed much local autonomy and invovled subject peoples in their rulership. After 1889 they began to lay more emphasis on Turkey as an Ethnic Concept. beibng "Turkish" was important. Many of their subject peoples resented this.
The Ottoman Turks in 1908 had recognized Sharif Hussein ibn Ali,as Sharif and Emir of Mecca. The Sharif was charged with protecting the cities of Mecca and Medina and their environs and ensuring the safety of pilgrims performing the Hajj. The Hajj is the annual Muslim Pilgrimage to Mecca.
In 1916 Sharif Hussein rebelled against the Ottomans and began the so-called "Great Arab Revolt."
The primary goal was to establish an independent and unified Arab state stretching from Aleppo to Aden. The British government allegedly had agreed to this.
Hussein and the Hashemites accompanied by T. E. Lawrence (aka "Lawrence of Arabia") of Arabia with backing from the British military's Egyptian Expeditionary Force, successfully fought and expelled the Ottoman military presence from much of the Hejaz and Transjordan. In 1918, the rebels occupied Damascus which had actually been captured by the Australian contingent in the British Army and NOT by the Arabs as is usually claimed.
The Arabs then proclaimed the Arab Kingdom of Syria, a short-lived monarchy that was led by Hussein's son Faisal.
The British were already obligated to the French by the Sykes-Picot Agreement.

In the Franco-Syrian War of 1920 the French defeated King Feisal son of Hussein. The region of Syria was eventually divided into several client states under the Mandate for Syria and the Lebanon. The British government declared the fugitive Faisal, who had been deposed in Syria, as the new king of Iraq.

At that time Transjordan was officially under British Rule but there were hardly any Britishers there. The region was loosely controlled by a few Beduin Tribes. Abdullah a son of Hussein with a band of his followers invaded the area in 1921 and declared himself king persuading the Bedouin chieftains to recognize him. .
The British felt that they had some kind of debt to the family of Hussein, so rather than forcibly eject him, recognized his claim. On May 15, 1923, Britain formally recognized the Emirate of Transjordan as a state under the leadership of Emir Abdullah.
Abdullah accepted British tutelage. The British strengthened his rule against local rebellions and raiders from Arabia.
A British soldier "Glub Pasha" (Lieutenant-General Sir John Bagot Glubb 1897-1986) was in charge of the army which included about 50 British Officers. These fought on the Arab side in the Israeli War of Independence of 1948. There was once a girl helping Brit-Am in the "office." Her gandfather had been among the Jewish defenders of Gush Etsion north of Hebron. They were captured by Jordanian soldiers who wanted to kill them. A British officer who was present prevented the massacre. Subsequently they were transferred to Jordan and later released as part of a Truce agreement.

As a result of this conflict in 1948 Jordan gained control of the Old City of Jerusalem and the West Bank. In 1949, Jordan formally annexed the West Bank. This angered Arab countries including Syria, Saudi Arabia and Egypt. Only Britain and Pakistan out of all nations of the world recognized this annexation.
Abdullah was assassinated in Jerusalem while attending Friday prayers at the entrance of the Al-Aqsa Mosque by a Palestinian in 1951. Abdullah was succeeded by his eldest son Talal who abdicated in 1953 in favor of his son Hussein. In 1958, Jordan and neighboring Iraq ruled over by his nephew, Faisal-2, formed the Arab Federation. This was dissolved when Faisal-2 was killed in a coup. In 1999, Abdullah-2 succeeded Hussein as King of Jordan.

Meanwhile in 1923 Hussein had formed the independent Kingdom of Hejaz in Arabia and then declared himself Caliph, i.e. ruler of all the Muslims. Hussein broke with the British partly over the Balfour Declaration. In 1925 the Hejaz (Mecca region) was conquered by Ibni Saud and became part of Saudi Arabia.

The Arab-majority Ottoman territories of the Middle East had been broken up into a number of League of Nations mandates, jointly controlled by the British and the French. The Ottoman Empire was formally dissolved in 1923. The defeated Ottoman Turks mainland in Anatolia came under a joint military occupation by the victorious Allies. This was gradually broken by the Turkish War of Independence, which established the present-day Republic of Turkey.