Hariharalaya

City · c. 802–1431 CE · in Southeast Asia

Capital of Khmer Empire (802–1431).

Yasodharapura (c. 802–1431 CE): Capital of Khmer Empire (802–1431).
Prague (800 CE): Capital of Duchy of Bohemia (896–1002), Kingdom of Bohemia (1202–1528), Holy Roman Empire (1346–1611), and 4 more.
Ribe (800 CE): Capital of North Sea Empire (1018–1035).
Kyoto (Heian-kyo) (794 CE): Emperor Kanmu moved the capital to Heian-kyo, which remained Japan's imperial capital until 1868.
Koumbi Saleh (c. 793–1200 CE): Capital of Ghana Empire (793–1200).
Nitra (c. 814 CE): Capital of Principality of Nitra (814–839).
Fez (789 CE): Capital of Idrisids (793–974), Marinid Sultanate (1250–1465), Wattasid dynasty (1472–1554), and 1 more.
Mashhad (818 CE): Capital of Afsharid Iran (1736–1756).
Dali (c. 779 CE): Capital of Nanzhao (779–902), Kingdom of Dali (947–1253).
Aínsa (c. 825 CE): Capital of Kingdom of Sobrarbe (825–829).

Around the same time and place

Angkor Wat (c. 1120 CE): Temple complex built in the first half of the 12th century under Suryavarman II, originally dedicated to Vishnu; the largest religious monument in the world.
Founding of the Khmer Empire (802 CE): Jayavarman II proclaimed himself universal monarch on Phnom Kulen in 802, traditionally marking the foundation of the Khmer Empire.
Pagan Kingdom unified (1044 CE): Anawrahta's accession in 1044 began the unification of the Irrawaddy valley under Pagan, the first Burmese empire, which built thousands of Buddhist temples.
Marco Polo’s return voyage from China (1291–1295 CE): After some 17 years in Yuan China, the Polos escorted a Mongol princess to the Ilkhanate, sailing from Quanzhou via Sumatra and India to Hormuz, then travelled overland to Trebizond and home to Venice in 1295.
Ayutthaya (1351–1767 CE): Capital of the Siamese kingdom of Ayutthaya, founded in 1351, which became one of the largest and most cosmopolitan cities in Asia before it was destroyed by Burmese forces in 1767.
Malacca Sultanate (c. 1400–1511 CE): Sultanate founded by Parameswara around 1400 that became the leading entrepôt of the Strait of Malacca and helped spread Islam through the archipelago.
Funan (c. 100–550 CE): Early Indianised state of the lower Mekong whose port at Óc Eo traded with both India and China from about the 1st to the 6th century.
Bagan (200–1293 CE): Capital of Pagan Kingdom (850–1293).