668
year

Year 668 (DCLXVIII) was a leap year starting on Saturday of the Julian calendar. The denomination 668 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Events
By place
Byzantine Empire
July 15 – Emperor Constans II is killed under mysterious circumstances in his bath, during a mutiny at Syracuse. The Byzantine court returns to Constantinople after an absence of 5 years, in which the Muslim-Arabs have made annual invasions and devastations of Anatolia. Probably assassinated by his chamberlain after a 27-year reign, Constans is succeeded by his son Constantine IV (the "Bearded"), alongside his brothers Heraclius and Tiberius as co-emperors.
Mezezius, Byzantine general and patrikios ("first patrician"), is proclaimed emperor by the army in Syracuse. Constantine IV organizes an expedition to suppress the military revolt in Sicily.
Europe
Ebroin, mayor of the palace, becomes de facto ruler of Neustria and (in theory) "of the Franks". According to Bede, he runs the nation's foreign policy and internal security.
Kotrag, ruler (khagan) of Great Bulgaria, leads the Khazars in overthrowing his brother Batbayan of the Onogurs, and moves south into the Carpathian Mountains.
This brief starts where responsible research should: with the source description of “668” as year. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as year. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Feb 27, 2026. The linked authority identifier is Q30116. None of the 0 selected statements returned an explicit reference.
The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “668”, its source revision and the description used here.
- Expand the search: follow 668 primary sources, 668 archive and year research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “668”?
- Which cited source is closest to the event, object or claim?
- What terminology or title could unlock a more precise catalogue search?
Search terms from this dossier
This entry incorporates text from “668” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.