3 Seas Europe. That became the major reason for the Grand Duchy of Lithuania seeking a union with Poland - political and military support against the growing power of the Duchy of Moscow. This relationship had two stages - the first was a peripheral personal joining, and then there was the full union. The first stage happened in 1385, and Origins Poland and Lithuania had close political ties before the 16th century. In fact, there had been a type of union between the two states since 1386 through royal marriages. However, the The fact that Poland and Lithuania merged voluntarily and fraternally was of vital importance, as evidenced by the Manifestation of the Unity of the Polish-Lithuanian Commonwealth in Horodło. Although held in 1861, as Poland was under partitions at that time, the gathering was attended by 10,000 participants from all over the country. In the same year, the dynastic bond between Poland and Lithuania was transformed into a constitutional relationship by the Acts of the Lublin Diet, which described the Polish-Lithuanian state as a Commonwealth of Both Nations (Rzeczpospolita Obojga Narodów). This was compounded by the extremely unfavourable geopolitical situation of the Polish-Lithuanian Commonwealth, which, in the first half of the 18th century, was unable to resist the influence of neighbouring states. The potential of the Polish-Saxon Union was not exploited at all. The struggle with Moscow continued over the next two centuries. Until 1569 the union of Lithuania and Poland remained a loose alliance by virtue of a common ruler. On July 1, 1569, a common Polish-Lithuanian parliament meeting in Lublin transformed the loose personal union of the two states into a Commonwealth of Two Peoples. While Poland and .

why did poland and lithuania unite