| Treaty of Lake Melno | |
|---|---|
 Map of the State of the Teutonic Order between 1260 and 1410. | |
| Context | Gollub War |
| Signed | 27 September 1422 |
| Location | Lake Melno |
| Ratified | 9–18 May 1423 |
| Condition | Approval by Pope Martin V |
| Parties | |
The Treaty of Melno (Lithuanian: Melno taika; Polish: Pokój melneński) or Treaty of Lake Melno (German: Friede von Melnosee) was a peace treaty ending the Gollub War. It was signed on 27 September 1422, between the Teutonic Knights and an alliance of the Kingdom of Poland and the Grand Duchy of Lithuania at Lake Melno (German: Melnosee, Meldensee; Polish: Jezioro Mełno), east of Graudenz (Grudziądz). The treaty resolved territorial disputes between the Knights and Lithuania regarding Lithuania Minor and Samogitia, which had dragged on since 1382, and determined the Prussian–Lithuanian border, which afterwards remained unchanged for about 500 years. A portion of the original border survives as a portion of the modern border between the Republic of Lithuania and Kaliningrad Oblast, Russia, making it one of the oldest and most stable borders in Europe.[1]