[3] It was a medieval agreement between the monarchs which listed the territorial possessions, rights to particular towns and similar aspects, but did not define the border.

The current Lithuanian–Russian border was established after World War II, when Königsberg and the territory around it was annexed by the Soviet Union.

[2] For example, at Lake Vištytis the border ran along the waterline of the beaches on the Lithuanian side, so anyone paddling in the water was technically crossing into Russia.

In early 2017, with increasing military activity and political tensions in the region, the Lithuanian government announced plans to reinforce the Kaliningrad/Ramoniškiai area border crossing with a fence 2 m (6 ft 7 in) in height, funded by NATO.

[5][6] On 13 September 2023, Lithuania banned vehicles with Russian license plates from entering its territory, in accordance with a decision by the European Union.

The proposed changes would expand its territorial waters by altering the maritime borders it shares with Finland and Lithuania, effective from January 2025.