864
year
Year 864 (DCCCLXIV) was a leap year starting on Saturday of the Julian calendar.
Events
By place
Europe
Spring – Emperor Louis II (the Younger) marches with a Frankish army against Rome. While en route to the papal city, he becomes ill, and decides to make peace with Pope Nicholas I.
July 25 – Edict of Pistres: King Charles the Bald orders defensive measures against the Vikings. He creates a large force of cavalry, which inspires the beginning of French chivalry.
Viking raiders, led by Olaf the White, arrive in Scotland from the Viking settlement of Dublin (Ireland). He rampages the country, until his defeat in battle by King Constantine I.
Robert the Strong, margrave of Neustria, attacks the Loire Vikings in a successful campaign. Other Viking raiders plunder the cities of Limoges and Clermont, in Aquitaine.
King Louis the German invades Moravia, crossing the Danube River to besiege the civitas Dowina (identified, although not unanimously, with Devín Castle in Slovakia).
Pepin II joins the Vikings in an attack on Toulouse. He is captured while besieging the Frankish city.
Begin with the source’s own compact description: “864” is year. The dossier treats that line as a proposition to test through year, not as a finished interpretation.
Why this record matters
The phrase “year” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Jul 25, 2026. The linked authority identifier is Q25041. None of the 0 selected statements returned an explicit reference.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. 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 “864”, its source revision and the description used here.
- Expand the search: follow 864 primary sources, 864 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 “864”?
- What terminology or title could unlock a more precise catalogue search?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “864” 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.