Amol

City · c. 866 CE · in Europe

Capital of Zaydi Alid dynasties (866–928), Ziyarid dynasty (936–979).

Olbia (c. 866 CE): Capital of Giudicato of Gallura (866–1209).
Porto Torres (c. 866 CE): Capital of Giudicato of Logudoro (866–1259).
Smolensk (863 CE): Capital of Principality of Smolensk (1056–1406).
La Seu d'Urgell (c. 870 CE): Capital of County of Urgell (870–1413).
Brunswick (861 CE): Capital of Duchy of Brunswick (1815–1870).
Zaranj (c. 861 CE): Capital of Saffarid Dynasty (861–899).
Sibenik (860 CE): Capital of Kingdom of Croatia (926–1098).
Beiting (c. 860–1138 CE): Capital of Qocho Kingdom (860–1138).
Badajoz (875 CE): Capital of Taifa of Badajoz (1010–1151).
Sort (c. 875 CE): Capital of County of Pallars (875–1011), County of Pallars Sobirà (1040–1201).

Around the same time and place

Silk Road (c. 130 BCE – c. 1450 CE): A network of overland caravan routes linking China with Central Asia, Persia and the Mediterranean, along which silk, spices, horses, religions, technologies and diseases travelled for more than 1,500 years.
Al-Khwarizmi's algebra (c. 820 CE): Al-Khwarizmi's treatise on solving linear and quadratic equations systematically founded algebra as a discipline; the word 'algebra' comes from al-jabr in its title.
Abbasid Caliphate (750–1258 CE): The Abbasid dynasty, descended from Muhammad's uncle, took the caliphate from the Umayyads and ruled from Iraq, presiding over the Islamic Golden Age.
House of Wisdom (c. 830 CE): An Abbasid centre of scholarship in Baghdad that flourished under Caliph al-Ma'mun, where scholars translated Greek, Persian and Indian works into Arabic.
Sogdians (c. 500 BCE – c. 900 CE): Iranian people of the Zeravshan valley around Samarkand and Bukhara whose merchants dominated trade along the Silk Roads, especially between the 4th and 8th centuries.
Palmyra (c. 261–1929 CE): Capital of Palmyrene Empire (261–269).
Al-Khwarizmi (c. 780 CE – 850 CE): A Persian mathematician and astronomer at the House of Wisdom whose works introduced algebra and Hindu–Arabic numerals to later scholars; the word 'algorithm' derives from his name.
Mashhad (818 CE): Capital of Afsharid Iran (1736–1756).