Union for the Liberation of Vilnius
The Union for the Liberation of Vilnius (Lithuanian: Vilniaus vadavimo sąjunga or Vilniui vaduoti sąjunga) was an organization established in 1925 to support Lithuanian territorial claims to Vilnius Region then part of the Second Polish Republic. With 27,000 members and 600,000 supporters in 1937, it was one of the most popular organizations in interwar Lithuania.
Source: Wikipedia — Union for the Liberation of Vilnius (CC BY-SA 4.0)