Sources & licenses
The event text on this timeline is not our writing. We carry one line from each source chronology verbatim, and record for every event where it came from and on what terms it may be reused. The “Sources” line in the detail panel is that event’s own. Coverage runs from 500 BC through 2025 — the current year is left out, because this year’s chronology is still a moving document.
Wikipedia chronologies — all four columns
- Korea: Korean Wikipedia 「한국사 연표」, English “Timeline of Korean history”
- China: English “Timeline of Chinese history”
- Japan: English “Timeline of Japanese history”
- United States: English “Timeline of pre–United States history” and the period articles “Timeline of United States history”
The body text is CC BY-SA 4.0. Each event’s detail panel links to the source article and to the revision (revid) as collected. Under the share-alike clause, the event text on this site may in turn be reused under CC BY-SA 4.0. The English originals are not translated yet — once a translation is attached, it carries the same terms.
National Institute of Korean History chronology — the Korea column
Where an entry in the Korea column matches the Korean History Database of the National Institute of Korean History (NIKH) by year and content, we carry that official entry alongside it (marked ◆). That entry is the official source and the precise date (including the lunar-calendar notation); each event offers “More official chronology for this year” for the remaining entries of the same year.
- Dataset: NIKH (Ministry of Education), 「한국역사자료 메타데이터 정보_연표」, Korea Open Data Portal 15051036 (2022-10 revision, 215,536 entries)
- Terms: KOGL (Korea Open Government License) · no restriction on the scope of use
- Range: ancient (2333 BC–937) · modern (1860–1945) · Republic of Korea (1945–2008) · thematic chronologies. Goryeo and Joseon (938–1859) are absent from this dataset, so the Korea column rests on Wikipedia alone for that stretch.
For China, Japan and the United States we found no official chronology with open terms (surveyed 2026-09). However authoritative a source may be, if its terms are closed we do not carry its text — we use it only for cross-checking and linking.
Names by perspective · importance
The name each country uses for an event comes verbatim from the sitelink titles of Wikidata (CC0). The “importance” shown in the detail panel ranks, within a column, how many Wikipedia language editions carry that entry; it is a device for deciding display density, not a historical judgement.