Lengvenis
| Lengvenis | |
|---|---|
Seal of Lengvenis, dating to 1379  | |
| Prince of Novgorod | |
| Reign | 1389–1392, 1406–1411 | 
| Predecessor | Dmitry Donskoy | 
| Successor | Vasily III Dmitriyevich | 
| Prince of Mstsislaw | |
| Reign | 1392–1431 | 
| Predecessor | Karigaila | 
| Born | c. 1360 | 
| Died | after 19 June 1431 | 
| Spouse | Maria Dmitrovna | 
| Dynasty | Gediminid | 
| Father | Algirdas | 
| Mother | Uliana of Tver | 
Lengvenis (c. 1360 – after 19 June 1431) was one of the sons of Algirdas, Grand Duke of Lithuania, who was the prince of Novgorod (1389–1392; 1406–1411). He was one of the most famous commanders of Vytautas the Great. He was baptized in the Eastern Orthodox rite as Semën to be titled the prince of Novgorod.