Karl August, Grand Duke of Saxe-Weimar-Eisenach
| Charles Augustus | |
|---|---|
Portrait by Heinrich Christoph Kolbe, 1822 | |
| Grand Duke of Saxe-Weimar-Eisenach | |
| Reign | 9 June 1815 – 14 June 1828 |
| Predecessor | Raised from duchy |
| Successor | Charles Frederick |
| Duke of Saxe-Weimar-Eisenach | |
| Reign | 20 September 1809 – 9 June 1815 |
| Predecessor | New creation from personal union |
| Successor | Raised to grand duchy |
| Duke of Saxe-Weimar | |
| Reign | 28 May 1758– 20 September 1809 |
| Predecessor | Ernest Augustus II |
| Successor | Union with Saxe-Eisenach |
| Regent | Dowager Duchess Anna Amalia |
| Duke of Saxe-Eisenach | |
| Reign | 28 May 1758– 20 September 1809 |
| Predecessor | Ernest Augustus II |
| Successor | Union with Saxe-Weimar |
| Regent | Dowager Duchess Anna Amalia |
| Born | 3 September 1757 Weimar, Duchy of Saxe-Weimar, Holy Roman Empire (now in Thuringia, Germany) |
| Died | 14 June 1828 (aged 70) Graditz, near Torgau, Province of Saxony, Kingdom of Prussia (now in Saxony, Germany) |
| Spouse | |
| Issue | |
| House | Saxe-Weimar-Eisenach |
| Father | Ernest Augustus II, Duke of Saxe-Weimar and Saxe-Eisenach |
| Mother | Duchess Anna Amalia of Brunswick-Wolfenbüttel |
| Religion | Lutheranism |
Karl August, sometimes anglicised as Charles Augustus (3 September 1757 – 14 June 1828), was the sovereign Duke of Saxe-Weimar and of Saxe-Eisenach (in personal union) from 1758, Duke of Saxe-Weimar-Eisenach from its creation (as a political union) in 1809, and grand duke from 1815 until his death. He is noted for the intellectual brilliance of his court.