# 421 > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/421 > Markdown URL: https://mediated.wiki/source/421.md > Source: https://en.wikipedia.org/wiki/421 > Source revision: 1349205007 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) For the airplane, see [Cessna 421](/source/Cessna_421). This article relies largely or entirely on a single source. Relevant discussion may be found on the talk page. Please help improve this article by introducing citations to additional sources. Find sources: "421" – news · newspapers · books · scholar · JSTOR (March 2019) Calendar year Years Millennium 1st millennium Centuries 4th century 5th century 6th century Decades 400s 410s 420s 430s 440s Years 418 419 420 421 422 423 424 v t e 421 by topic Leaders Political entities State leaders Religious leaders Categories Deaths Establishments Disestablishments v t e 421 in various calendars Gregorian calendar 421 CDXXI Ab urbe condita 1174 Assyrian calendar 5171 Balinese saka calendar 342–343 Bengali calendar −173 – −172 Berber calendar 1371 Buddhist calendar 965 Burmese calendar −217 Byzantine calendar 5929–5930 Chinese calendar 庚申年 (Metal Monkey) 3118 or 2911 — to — 辛酉年 (Metal Rooster) 3119 or 2912 Coptic calendar 137–138 Discordian calendar 1587 Ethiopian calendar 413–414 Hebrew calendar 4181–4182 Hindu calendars - Vikram Samvat 477–478 - Shaka Samvat 342–343 - Kali Yuga 3521–3522 Holocene calendar 10421 Iranian calendar 201 BP – 200 BP Islamic calendar 207 BH – 206 BH Javanese calendar 305–306 Julian calendar 421 CDXXI Korean calendar 2754 Minguo calendar 1491 before ROC 民前1491年 Nanakshahi calendar −1047 Seleucid era 732/733 AG Thai solar calendar 963–964 Tibetan calendar ལྕགས་ཕོ་སྤྲེ་ལོ་ (male Iron-Monkey) 547 or 166 or −606 — to — ལྕགས་མོ་བྱ་ལོ་ (female Iron-Bird) 548 or 167 or −605 This is a [dynamic list](https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Lists#Dynamic_lists) and may never be able to satisfy particular standards for completeness. You can help by [editing the page](https://en.wikipedia.org/wiki/Special:EditPage/421) to add missing items, with references to [reliable sources](https://en.wikipedia.org/wiki/Wikipedia:Reliable_sources). [Solidus](/source/Solidus) of Emperor [Constantius III](/source/Constantius_III) Year **421** (**[CDXXI](/source/Roman_numerals)**) was a [common year starting on Saturday](/source/Common_year_starting_on_Saturday) of the [Julian calendar](/source/Julian_calendar). At the time, it was known as the **Year of the Consulship of [Agricola](/source/Agricola_(consul_421)) and [Eustathius](/source/Eustathius_(consul))**[1] (or, less frequently, **year 1174 *[Ab urbe condita](/source/Ab_urbe_condita)***). The denomination 421 for this year has been used since the early medieval period, when the [Anno Domini](/source/Anno_Domini) [calendar era](/source/Calendar_era) became the prevalent method in Europe for naming years. ## Events ### By place #### Roman Empire - [February 8](/source/February_8) – [Constantius III](/source/Constantius_III) is appointed co-emperor (*[Augustus](/source/Augustus_(title))*) with his ineffectual brother-in-law, [Honorius](/source/Honorius_(emperor)), and becomes the real ruler of the [Western Roman Empire](/source/Western_Roman_Empire).[2] - [March 25](/source/March_25) – [Venice](/source/Venice) is founded at twelve o'clock noon (according to legend) with the dedication of the first church, [San Giacomo](/source/San_Giacomo_di_Rialto), at the islet of [Rialto](/source/Rialto) ([Italy](/source/Italy)). - [June 7](/source/June_7) – Emperor [Theodosius II](/source/Theodosius_II) marries [Aelia Eudocia](/source/Aelia_Eudocia), a woman of Greek origin. The [wedding](/source/Wedding) is celebrated at [Constantinople](/source/Constantinople) with [chariot racing](/source/Chariot_racing) in the [Hippodrome](/source/Hippodrome_of_Constantinople).[3] - [September 2](/source/September_2) – Constantius III dies suddenly of an illness; his wife [Galla Placidia](/source/Galla_Placidia) becomes, for the second time, a [widow](/source/Widow).[4] - [Castinus campaign against the Franks](/source/Castinus_campaign_against_the_Franks): A Roman army under command of [Castinus](/source/Castinus) fights against the Franks in Northern Gaul. #### Europe - [Rugila](/source/Rugila), chieftain of the [Huns](/source/Huns), attacks the [dioceses](/source/Roman_diocese) of [Dacia](/source/Diocese_of_Dacia) and [Thrace](/source/Diocese_of_Thrace) ([Balkans](/source/Balkans)). Theodosius II allows [Pannonian](/source/Pannonia_(Roman_province)) [Ostrogoths](/source/Ostrogoths) to settle in Thrace, to defend the [Danube](/source/Danube) frontier.[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed)*] - The [Franks](/source/Franks) conquer new territories in their kingdom and sack the old [Roman](/source/Roman_Empire) capital *[Augusta Treverorum](/source/Augusta_Treverorum)* (modern [Trier](/source/Trier)). #### Persia - [Roman–Sassanid War](/source/Roman%E2%80%93Sassanid_War_(421%E2%80%93422)): Theodosius II starts a war against the [Sassanids](/source/Sassanids), sending an expeditionary force under command of [Ardaburius](/source/Ardabur_(consul_427)), and invades [Mesopotamia](/source/Mesopotamia). - Autumn – Ardaburius devastates [Arzanene](/source/Aghdznik) ([Armenia](/source/Kingdom_of_Armenia_(antiquity))) and forces the Persians to retreat to [Nisibis](/source/Nusaybin) ([Syria](/source/Syria)). King [Bahram V](/source/Bahram_V) allies himself with the [Lakhmid Arabs](/source/Lakhmids) of [Hirah](/source/Al-Hirah). ## Deaths - [September 2](/source/September_2) – [Constantius III](/source/Constantius_III), emperor of the [Western Roman Empire](/source/Western_Roman_Empire)[4] - [Jin Gongdi](/source/Emperor_Gong_of_Jin), last emperor of the [Jin Dynasty](/source/Jin_Dynasty_(265-420)) (b. [386](/source/386)) - [Li Xun](/source/Li_Xun_(Western_Liang)), ruler of the Chinese state [Western Liang](/source/Western_Liang_(Sixteen_Kingdoms)) - [Mary of Egypt](/source/Mary_of_Egypt), [patron saint](/source/Patron_saint) (approximate date) - [Ravina I](/source/Ravina_I), [rabbi](/source/Rabbi) (teacher) and Jewish [Talmudist](/source/Talmud) ## References 1. **[^](#cite_ref-1)** Ross, Kelly L. ["Consuls of the Roman Empire"](https://friesian.com/romconsl.htm). *fresian.com*. Retrieved March 12, 2026. 1. **[^](#cite_ref-2)** Stewart Irvin Oost, *Galla Placidia Augusta: A Biographical Essay* (Chicago: University Press, 1968), p. 163 1. **[^](#cite_ref-3)** Holum, Kenneth G. (October 25, 1989). *Theodosian Empresses: Women and Imperial Dominion in Late Antiquity*. University of California Press. p. 115. [ISBN](/source/ISBN_(identifier)) [978-0-520-06801-8](https://en.wikipedia.org/wiki/Special:BookSources/978-0-520-06801-8). 1. ^ [***a***](#cite_ref-Oost-166_4-0) [***b***](#cite_ref-Oost-166_4-1) Oost, *Galla Placidia Augusta*, p. 166 --- Adapted from the Wikipedia article [421](https://en.wikipedia.org/wiki/421) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/421?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.