Finland: Polity Style: 1808-2026

16/28 Mar 1808	Russian imperial declaration on annexation of Finnish lands in possession of Sweden communicated to the Great Powers (Russia Laws Complete Collection I, 30:22899)
20 Mar/1 Apr 1808	annexation of Finland is proclaimed, manifesto of the Emperor (Russia Laws Complete Collection I, 30:22911)
25 Dec 1808/6 Jan 1809	grand princely title of Finland is included in the Russian imperial title, decree of the Emperor (Russia Laws Complete Collection I, 30:23421)
25 Dec 1808/6 Jan 1809 - 2/15 Nov 1917	Storfurstendömet Finland \| Grand Principality of Finland [1]
1/13 Oct 1809	the provinces (hövdingadömen) comprising the territory of Finland, formerly possessions of Sweden, are ceded to the Russian Empire in accordance with a treaty concluded by representatives of the King of Sweden and the Emperor of All Russia at Fredrikshamn (Hamina) on 5/17 Sep 1809, effective upon the exchange of ratifications in St. Petersburg on 1/13 Oct 1809 (Martens NR, 1:19-29; Skjöldebrand Memoirs, 3:244-247)
27 Oct/9 Nov 1917	supreme authority exercised by the Grand Prince is transferred to a Council of Regency to be elected by the Eduskunta (Diet), resolution of the Eduskunta of 27 Oct/9 Nov 1917 (Parliament Proceedings - Finnish Edition, Session 9 Nov 1917, p. 47; Parliament Proceedings - Swedish Edition, Session 9 Nov 1917, p. 10) [2]
2/15 Nov 1917	supreme authority exercised by the Grand Prince is transferred to the Eduskunta, resolution of the Eduskunta of 2/15 Nov 1917 (Parliament Proceedings - Finnish Edition, Session 15 Nov 1917, p. 145; Parliament Proceedings - Swedish Edition, Session 15 Nov 1917, p. 19)
2/15 Nov 1917 -	Suomi = Finland [3][4]
23 Nov/6 Dec 1917	principle of state sovereignty included in the declaration of the Senate of 21 Nov/4 Dec 1917 is approved, resolution of the Eduskunta of 23 Nov/6 Dec 1917 (Parliament Proceedings - Finnish Edition, Session 6 Dec 1917, p. 366; Parliament Proceedings - Swedish Edition, Session 6 Dec 1917, p. 68)

Also in limited official use: Velikoe Knjažestvo Finljandskoe (Великое Княжество Финляндское) in Russian; Suomen suuriruhtinaanmaa in Finnish.
Eduskunta assumed sovereign authority de facto by passing a resolution on appointment of a Council of Regency (Finnish: valtionhoitajakunta; Swedish: statsföreståndarnämnd) on 27 Oct/9 Nov 1917. The Council was not elected and the Eduskunta passed a resolution on 2/15 Nov 1917 de iure accepting the supreme authority in Finland.
After the promulgation of the Form of Government (Constitution) 17 Jul 1919, Suomen tasavalta = Republiken Finland becomes officially accepted name of the state, although it was not given any Constitutional recognition except for a mention in the presidential affirmation of office.
Alternative style used in addition to Suomi by a dissident government (Suomen kansanhallitus) formed in Terijoki (now Zelenogorsk, Russia) between 1 Dec 1939 and 12 Mar 1940: Suomen kansanvaltainen tasavalta (Finnish Democratic Republic).