| 12 Oct 1920 |
Government of Central Lithuania established, decree of the Commander-in-Chief of the Central Lithuanian Army of 12 Oct 1920 (Central Lithuania Official Bulletin, No. 1, 17 Oct 1921, pp. 1-2) |
| 12 Oct 1920 - 24 Mar 1922 |
Litwa Środkowa | Central Lithuania |
| 20 Feb 1922 |
Ziemia Wileńska (formerly Central Lithuania) is proclaimed part of Poland, resolution of the Assembly of Wilno (Sejm Wileński) passed 20 Feb 1920 at Wilno (now Vilnius) (Central Lithuania Official Bulletin, No. 7, 9 Mar 1922, pp. 73-74) |
| 2 Mar 1922 |
Act of unification signed by the representatives of the government of Poland and the members of the Assembly of Wilno, public ceremony, Warsaw (Poland Law Bulletin, No. 20, 24 Mar 1922, pp. 331-332) [1] |
| 24 Mar 1922 |
Resolution of the Constituent Assembly (Sejm Ustawodawczy) of Poland on approval of the act of unification of 2 Mar 1922 passed 24 Mar 1922 (effective upon publication) (Poland Law Bulletin, No. 20, 24 Mar 1922, pp. 331-332) |
| 13 Apr 1922 |
Government of Poland assumed the administration of Ziemia Wileńska in accordance with a law of 6 Apr 1922 (effective upon publication) (Poland Law Bulletin, No. 26, 13 Apr 1922, pp. 400-401) |
