on this day, 29 engagements
Battles fought on 21 August
29 engagements in the atlas were fought on 21 August between 1238 and 1975: 22 battles, 6 sieges and 1 naval action. Among them: Battle of Charleroi (1914), Battle of the Tenaru (1942), Battle of the Ardennes (1914), Conquest of Ceuta (1415).
Engagements by date
| Date | Engagement | Place | War |
|---|---|---|---|
| 21 August 1238 | Battle of Örlygsstaðir | Icelandic Commonwealth | Age of the Sturlungs |
| 21 August 1415 | Conquest of Ceuta | Ceuta under Muslim rule | Moroccan–Portuguese conflicts |
| 21 August 1541 | Siege of Buda | Buda | |
| 21 August 1570 | Siege of Reval | Tallinn | Livonian War |
| 21 August 1653 | Siege of Suczawa | Suceava | Khmelnytsky Uprising |
| 21 August 1656 | Siege of Riga | Riga | Second Northern War |
| 21 August 1673 | Battle of Texel | Texel | |
| 21 August 1689 | Battle of Dunkeld | Dunkeld | Jacobite risings |
| 21 August 1778 | Siege of Pondicherry | Pondicherry | Anglo-French War of 1778–1783 |
| 21 August 1796 | Battle of Amberg | Amberg | War of the First Coalition |
| 21 August 1808 | Battle of Vimeiro | Vimeiro | Peninsular War |
| 21 August 1808 | Battle of Karstula | Karstula | Finnish War |
| 21 August 1838 | Battle of Portada de Guías | Lima | War of the Confederation |
| 21 August 1860 | Battaglia di Piazza Duomo | Reggio Calabria | Unification of Italy |
| 21 August 1863 | Lawrence Massacre | Lawrence, Kansas | American Civil War |
| 21 August 1863 | Second Battle of Chattanooga | Chattanooga, Tennessee | American Civil War |
| 21 August 1863 | Skirmish near Brooklyn, Kansas | Kansas | American Civil War |
| 21 August 1864 | Second Battle of Memphis | Memphis, Tennessee | American Civil War |
| 21 August 1864 | Battle of Summit Point | Summit Point, West Virginia | American Civil War |
| 21 August 1914 | Battle of Charleroi | Charleroi | World War I |
| 21 August 1914 | Battle of the Ardennes | Ardennes | World War I |
| 21 August 1914 | Battle of Lai | World War I | |
| 21 August 1915 | Battle of Hill 60 (Gallipoli) | Gallipoli | World War I |
| 21 August 1915 | Battle of Scimitar Hill | Suvla Bay | World War I |
| 21 August 1942 | Battle of the Tenaru | Guadalcanal | Pacific War |
| 21 August 1944 | Battle of Marseille | Marseille | World War II |
| 21 August 1944 | Battle of Surkonty | Surkanty | |
| 21 August 1968 | Battle for Czechoslovak Radio | Český rozhlas headquarters | Cold War |
| 21 August 1975 | Aleria standoff | Aléria |
Only engagements recorded to the day are listed. Dates before 1582 are Julian, as recorded.