Lithuania's city Vilnius is its capital.
The Act of Reinstating Independence of Lithuania ( Lietuvos Valstybės atkūrimo aktas ) or Act of February 16 was signed by the Council of Lithuania on February 16 , 1918 , proclaiming the restoration of an independent State of Lithuania , governed by democratic principles , with Vilnius as its capital . Lithuania . As World War I neared its end , Lithuania 's Act of Independence was signed on 16 February 1918 , declaring the founding of the modern Republic of Lithuania . Vilnius ( [ ˈvʲɪlʲnʲʊs ] , see also other names ) is the capital of Lithuania and its largest city , with a population of 542,664 .