Say'un

Seiyun
The Sultan Al Kathiri Palace, the most prominent landmark of Seiyun.
Seiyun Location in Yemen
Coordinates: 15°58′N 48°47′E / 15.967°N 48.783°E / 15.967; 48.783Coordinates: 15°58′N 48°47′E / 15.967°N 48.783°E / 15.967; 48.783
Country	Yemen
Governorate	Hadhramaut
Population (2006)
• Total	75 700
Time zone	Yemen Standard Time (UTC+3)

Say'un — (also transliterated as Saywun or Seiyun; Arabic: سيئون‎‎  Hadhrami pronunciation: [seːˈwuːn], Literary Arabic: [sæjˈʔuːn]) — is a city in Hadhramaut region, Hadhramaut Governorate of Yemen. It is located in the middle of the Hadhramaut valley, about 360km from Mukalla, the capital of Mukalla District and the largest city in the area, via western route. It is also 12km away from Shibam and 35km away from Tarim, other large cities in Hadramaut valley.

It is said that the origin of the city was a resting point for travelers. There was a cafe with a woman named Seiyun there, and the area was named after her in her honor. Since then, the city has become the largest area of Hadhramaut valley. The most prominent villages surrounding the city including Madurah, Merida, Burr, Hazkir, and Houta Sultana.

It is served by Seiyun Airport. It is also well known for the Seiyun Palace of the Sultan of Kathiri built in 1920s by mud and stones. It is overseeing the market place for merchants coming from outside.

Seiyun is first mentioned in the beginning of the 4th-century, which dates back to the reign of King Dhamar who ruled at the beginning of the 4th-century the area around Hadhramaut Valley and known for destroying sixty thousand columns in the area. Destruction of the columns confirms that the Hadhramaut region was undergoing an economic prosperity owing from spread of grape cultivation in large areas under the climatic conditions different from the current circumstances.

Seiyun during the Islamic period emerged as a village in the era of the Rashidun Caliphate. It was administratively followed by the city of Tarim. This was the case during the Umayyad period as well. In 708, it became administratively affiliated with the city of Shibam, however the son of Haritha had lead the revolution in 1179. But it gained its autonomy only in the year 1501 when it became the capital of the valley in the era of Badr Abu Tuwairq (1501-1556), where an administrative unit consisted of a sultanate that extended from Ain Ba to the west of the city of Dhofar was founded. In the 18th-century, Yafa conquered the cities of Hadhramaut and took over many parts of Seiyun, where the state was established. In 1852, it became the capital of the State of Kathiri (Aden-Kathiri) which was within the British Aden Protectorate (1869 - 1963). Its fortified fortress, the Sultan's Palace, was the seat of Sultan al-Kathiri. Postage stamps from the Sultanate were sometimes inscribed "Kathiri State of Seiyun." After the independence from British colonialism, Seiyun became the capital of the Southern district in the fifth province of Hadhramaut.