Ji

City · c. 337 CE · in Central Asia

Capital of Former Yan (337–370).

Ye (c. 337–576 CE): Capital of Later Zhao (337–351), Northern Qi (555–576).
Wiryeseong (c. 347 CE): Capital of Baekje (347–660).
Guwahati (c. 353 CE): Capital of Kamarupa Kingdom (353–1138).
Puhar (c. 353 CE): Capital of Kalabhra Dynasty (353–600).
Banavasi (c. 353 CE): Capital of Kadamba Empire (353–525).
Linfen (c. 306 CE): Capital of Former Zhao (306–329).
San Marino (301 CE): Capital of Republic of San Marino (1797–1799).
Gyeongju (c. 378 CE): Capital of Silla (378–681), Unified Silla (682–892).
Lanzhou (c. 387 CE): Capital of Western Qin (387–431).
Pingcheng District (c. 387 CE): Capital of Northern Wei (387–533).

Around the same time and place

Yayoi period (c. 300 BCE – c. 300 CE): Era when wet-rice farming and metalworking spread to Japan from the continent; the Yoshinogari site is a major settlement.
Silla (c. 57 BCE – c. 935 CE): Kingdom with its capital at Gyeongju, traditionally founded in 57 BCE, that unified most of Korea in the 7th century.
Goguryeo (c. 37 BCE – c. 668 CE): Kingdom traditionally founded by Jumong in 37 BCE that grew to rule northern Korea and Manchuria.
Baekje (c. 18 BCE – c. 660 CE): Kingdom in southwestern Korea, traditionally founded in 18 BCE, a conduit of culture and Buddhism to Japan.
Wang Xizhi (303 CE – 361 CE): Calligrapher of the Eastern Jin, revered as the "Sage of Calligraphy".
Gwanggaeto the Great (374 CE – 413 CE): King of Goguryeo whose conquests greatly expanded the kingdom in Manchuria and Korea.
Battle of Fei River (383 CE): Eastern Jin forces defeated a much larger army of the Former Qin, preserving the southern dynasties.
Gungnae (c. 3–427 CE): Capital of Goguryeo (3–427).