255
year
Year 255 (CCLV) was a common year starting on Monday of the Julian calendar. At the time, it was known in Rome as the Year of the Consulship of Valerianus and Gallienus (or, less frequently, year 1008 Ab urbe condita). The denomination 255 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
China
Sima Shi quells Guanqiu Jian and Wen Qin's rebellion.
March 23 – Sima Shi passes away.
Sima Zhao, Sima Shi's younger brother, inherits his brother's authority.
By topic
Science
Ma Jun, Chinese mechanical engineer from Cao Wei, invents the south-pointing chariot, a path-finding directional compass vehicle that uses a differential gear, not magnetics.
Births
January 6 – Marcellus I, bishop of Rome (d. 309)
Dorotheus of Tyre, Syrian bishop and martyr (d. 362)
Zhang Gui, Chinese governor of the Jin Dynasty (d.
This brief starts where responsible research should: with the source description of “255” 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.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 25, 2026. The linked authority identifier is Q32344. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1008.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. 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
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The closest primary source, responsible institution and strongest cited specialist reference.
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- Establish the record: confirm the title “255”, its source revision and the description used here.
- Expand the search: follow 255 primary sources, 255 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
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This entry incorporates text from “255” 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.