In addition to the oasis, the county also includes the giant Empty Quarter desert, making it the largest governorate in Saudi Arabia in terms of area.

The Empty Quarter has the world's largest oil fields [citation needed], and connects Saudi Arabia to Qatar, the UAE, and Oman.

[5] This was determined by tombs that date back to five thousand years that were discovered on the coasts of Al-Ahsa and the neighboring island Bahrain.

Their description of their city came from the Greek traveler Strabo, who said about Al-Ahsa:[10] "It was founded by Chaldean immigrants from Babylon in a swampy land, and it was built of salt stones, eighty thousand cubits away from the sword of the sea.

"The Greek historian Polybius also described Al-Ahsa as an important commercial center, one of the active markets in the Arab countries, and a crossroads for the caravan routes coming from southern Arabia, the Levant, the Hijaz, Iraq and India.

[12] He crossed the Tigris, heading to it to seize its treasures, but its people, fearing them for their city and out of their love for peace and in order to preserve their freedom that they cherished, sent a delegation to him carrying a large gift of gold and precious stones.

So Antiochus accepted the gift And he closed back to his country, and perhaps the barren desert and the adventure of the trip was the main reason that convinced the Seleucid king to return from his determination.

[13] Al-Ahsa then became a part of a city belonging to the territory of Bahrain at that time, located between Ras Al-Qara mountain, Abu Hasis mountain, and the northern part of Jabal al-Qarah in Al-Ahsa today a place now called the town of Al-Kawarij.

[16] In 899 A.D., the region came under the control of the Qarmatian leader, Abu Tahir al-Jannabi, and was declared independent from the Abbasid Caliphate of Baghdad.

Al-Ahsa subsequently fell under the rule of the Bahrani dynasty of the Usfurids, followed by their relatives, the Jabrids, who became one of the most formidable powers in the region, retaking the islands of Bahrain from the princes of Hormuz.

[citation needed] The Ottomans were expelled from Al-Ahsa in 1670, and the region came under the rule of the chiefs of Banu Khalid tribe.

Al-Ahsa, along with Qatif, was incorporated into the Wahhabist Emirate of Diriyah in 1795, but returned to Ottoman control in 1818 with an invasion ordered by Muhammad Ali of Egypt.

In 1913, ibn Saud, the founder of modern Saudi Arabia, annexed Al-Ahsa and Qatif into his domain of Najd.

[18] 899: Al-Ahsa comes under control of the Qarmatian leader, Abu-Sa'id Jannabi, and is declared independent from the Abbasids of Baghdad.

1440: The Jabrids take over Al-Ahsa, Qatif, Bahrain, and Kish Island, and extend their influence to eastern Nejd.

1521: Jabrid kingdom falls to the Muntafiq tribe of southern Iraq, who rule Al-Ahsa on behalf of the Ottoman Empire.

Natural fresh-water springs have surfaced in the region for millennia, encouraging human habitation and agricultural efforts (date palm cultivation especially) since prehistoric times.

The Saudi Ministry of Agriculture established a factory to process its rich date harvest at the rate of five tons daily.

[1] The Ministry of Agriculture has set up a factory to process its rich output of dates, amounting to five tons daily.

It enjoys the benefit of copious reserves of underground water which has allowed the area to develop its agricultural potential.

To counter this problem, the Kingdom has planted large barriers of trees to prevent the wind-borne sand from damaging inhabited and agricultural areas.

Many pictures of old Al-Ahsa and the Eastern Province were taken by the Danish explorer and convert to Islam Knud Holmboe (1902–1931) in his travels through the Middle East.