The world in AD 900

Africa

Ahmad ibn Tulun, the Abbasid governor of Egypt, ruled from 868 to 884 and founded a state that his family, the Tulunids, held until 905. The Discover Islamic Art database of the Museum With No Frontiers dates his new capital, al-Qata’i, to 870 and his congregational mosque there to 879, a date taken from a foundation plaque in kufic script fixed to one of its piers. The mosque is the only building of al-Qata’i still standing, and its minaret, with a staircase that winds around the outside, copies the minaret of the Great Mosque of Samarra in Iraq. Farther west a rival caliphate was nine years away: Farhad Daftary, in the Encyclopaedia Iranica, dates the founding of the Fatimid state in Ifriqiya to 909 and its move to Egypt to 973.

West Asia

The caliph al-Mu’tadid reigned in Baghdad from 892 to 902, but C. Edmund Bosworth, in the Encyclopaedia Iranica, dates clear signs of the caliphate’s disintegration to the second half of the ninth century. About 892 the caliph al-Mu’tamid appointed a commander from Transoxania, Muhammad ibn Abi’l-Saj, governor of Azerbaijan and Armenia, and his family kept those provinces for nearly 40 years while the caliph’s rights, tribute among them, were often ignored. A religious challenge was forming at the same time. In 899 Abd Allah al-Mahdi, head of the Ismaili movement, openly claimed the imamate; Daftary writes that the Ismailis who refused him became known as the Qarmatians, while those who accepted him went on to found the Fatimid caliphate.

• What was the House of Wisdom in Baghdad, and what did it translate?AD 830

Europe

Leo VI, known as Leo the Wise, had ruled Byzantium since 886, and Dumbarton Oaks, in its online exhibit of imperial seals, calls his reign “one of internal success and external setback.” His war with Symeon of Bulgaria began in 894, a defeat in 896 left Byzantium paying tribute for peace, and in Sicily Taormina fell in 902, ending the province Justinian I had created in the sixth century; at home Leo sponsored collections of law and military practice, the Basilika and the Taktika. In England, the Anglo-Saxon Chronicle enters under the year 901 that Alfred, son of Ethelwulf, died “six nights before the mass of All Saints,” king over all the English except the part under the Danes, after a reign of “one year and a half less than thirty winters.” His son Edward took the government, and a kinsman, Prince Ethelwald, at once rose against him and went over to the Danish army in Northumbria.

• The Oseberg ship: buried in 834, dug out in 1904AD 834
• Was Charlemagne surprised by his coronation in 800?AD 800
• Alcuin's letters on Lindisfarne, 793, and a cemetery dug since 2016AD 793
• When were Vikings in North America? A solar storm says AD 10211021

East Asia

The Tang dynasty had not recovered from the rebellion that salt traders including Huang Chao began in 875, which took Luoyang and Chang’an before its defeat in 884. Ulrich Theobald’s history of the dynasty describes how power then passed to the generals who had crushed it, above all the Shatuo Turk Li Keyong, Zhu Quanzhong and Li Maozhen. The emperor Zhaozong, placed on the throne by a eunuch in 888, fell into the hands of Li Maozhen and the palace eunuchs until Zhu defeated them in 903 and moved the capital to Luoyang; in 907 Zhu made the last Tang emperor abdicate and founded the Later Liang. For Korea, Columbia University’s Asia for Educators timeline gives 890 to 936 as the Later Three Kingdoms, a period that ended 18 years after the Koryo dynasty was founded in 918.

South Asia

Between 889 and 900 the Khmer king Yasovarman I, son of Indravarman I, moved his capital northwest to the plains near the hill of Phnom Bakheng. The National Library of Australia, in a teaching module on the Khmer empire, gives the new city’s name as Yasodharapura, “City that Maintains Glory,” also known as Angkor, and notes that a raised causeway linked it to the old capital, Hariharalaya. Yasovarman also completed the Eastern Baray, a large reservoir. For the Indian subcontinent in 900, the sources cited below give no account.

• Why did Rajendra Chola send a fleet against Srivijaya in about 1025?1025

Central Asia

Ismail ibn Ahmad had governed Bukhara for his brother Nasr for nearly two decades before Nasr’s death in 892 made him ruler of all Transoxania, with Bukhara as his capital. Bosworth writes that Ismail won his greatest fame by defeating and capturing the Saffarid Amr ibn Layth in a battle near Balkh, probably in March 900, after the caliph had granted Amr eastern Persia and Transoxania. The caliph then named Ismail governor of Khorasan, Sistan, Rayy, Tabaristan and Isfahan, although later Samanid amirs kept only Khorasan and Transoxania. Ismail still named the caliph in the Friday sermon and on his coins, but Bosworth finds no evidence that he ever sent regular tribute to Baghdad.

• A sealed room at Mogao, opened in 1900: the Dunhuang Library Cave1000
• Did one battle in 751 carry papermaking to the West?AD 751

The Americas

A stalagmite from Grutas Tzabnah, a cave near Tecoh in Yucatán, laid down one layer a year, and in 2025 Daniel James and his colleagues read from it an extreme drought that began in 894, give or take six years, lasted four years, and after a single wet year gave way to five more years of wet-season drought. The team places the peak of hieroglyphic writing at nearby Uxmal in a short span from 895 to 907, and writes that “Old Chichén” declined with these droughts while “New Chichén” recovered and flourished into the late 900s, although they add that Chichén Itzá’s chronology is still debated. In the Andes, Erik Marsh and his colleagues, modeling radiocarbon dates from Tiwanaku in 2023, found that burials in formal tombs at the city stopped around 910, about a century before permanent residence there ended around 1010.

• How Did the Maya Track the Cycle of Venus — Without a Telescope?AD 900
• Three painted rooms at Bonampak, c. 790, entered by outsiders in 1946AD 790
• Who carried 200,000 trees into Chaco Canyon, and why did they leave?1050

Oceania

Sediment from Lake Te Roto on Atiu, in the southern Cook Islands, preserves fecal sterols from pigs or humans on an island landscape that had shown no earlier trace of them. David Sear and his colleagues, publishing in 2020, give the first such layer a modeled date between 800 and 966, with a midpoint of 883, and read it as discovery around AD 900, followed by colonization around 1000 and heavy disturbance of the lake’s surroundings from about 1100. Their evidence points to a drought of about 200 to 400 years in the likely source region to the west, which they propose helped set off the first voyages east. The sources cited below give no account of Australia or New Guinea in this century.

Sources

• Museum With No Frontiers, Discover Islamic Art: "Mosque of Ahmad Ibn Tulun"
• Encyclopaedia Iranica, Farhad Daftary: "Fatimids" (1999)
• Encyclopaedia Iranica, C. Edmund Bosworth: "ʿAbbasid Caliphate in Iran" (1982)
• Dumbarton Oaks, God's Regents on Earth: A Thousand Years of Byzantine Imperial Seals: "Leo VI (886–912)"
• Yale Law School, Avalon Project: "The Anglo-Saxon Chronicle: Tenth Century"
• ChinaKnowledge.de, Ulrich Theobald: "Tang Dynasty: Political History"
• Columbia University, Asia for Educators: "Korea: Timeline of Historical Periods"
• National Library of Australia, Digital Classroom: "The rise of Angkor and the Khmer Empire"
• Encyclopaedia Iranica, C. Edmund Bosworth: "Esmāʿīl, b. Aḥmad b. Asad Sāmānī" (1998)
• Science Advances via PubMed Central, James and colleagues: "Classic Maya response to multiyear seasonal droughts in Northwest Yucatán, Mexico" (2025)
• PLoS One via PubMed Central, Marsh and colleagues: "The center cannot hold: A Bayesian chronology for the collapse of Tiwanaku" (2023)
• PNAS via PubMed Central, Sear and colleagues: "Human settlement of East Polynesia earlier, incremental, and coincident with prolonged South Pacific drought" (2020)