The Third Bulgarian Kingdom Exposition comprises the period from the restoration of the Bulgarian State in 1878 to 1946 when Bulgaria was declared a People’s Republic. The Berlin Treaty terms (1878) unjustly divided the state into several parts – the Principality of Bulgaria, vassal to the Ottoman Empire and the Province of Eastern Rumelia which was under the direct political and military power of the Sultan. More than 2.5 millions of Bulgarians remained outside the boundaries of the Principality of Bulgaria.

The basic moments in the political, economic and cultural development of the Third Bulgarian Kingdom are shown by means of over 600 exhibits: the adoption of the Tarnovo Constitution (the 16th of April, 1879) by the Constituent Assembly; the choice of the first head of state of free Bulgaria – Kniaz (Prince) Alexander I (1879); the Unification of the Principality of Bulgaria and Eastern Rumelia and the following Serbian – Bulgarian War (1885); the Ilinden – Preobrazhenie Uprising (1903); the Proclamation of the Independence of Bulgaria and the Declaration of the Bulgarian Kingdom (1908); the Wars for the national unification (1912 – 1913, 1915 – 1918), the reversion of Southern Dobrudzha to Bulgaria (1940), the saving of the Bulgarian Jews from deportation to the Nazi concentration camps (1943), the participation of the country in the Nazism defeat (1944 – 1945), the Proclamation of Bulgaria as People’s Republic (1946).

The exposition has given considerable place to the Bulgarian monarchs: Kniaz (Prince) Alexander I, Kniaz (Prince) [from 1908 – Tsar (King)] Ferdinand I and Tsar (King) Boris III, to a number of eminent politicians, scientists, writers and cultural figures who played a significant role in the establishment and development of Bulgaria and in its transformation into a modern state by the European model: Todor Burmov, Dragan Tsankov, Petko Karavelov, Konstantin Stoilov, Stefan Stambolov, Alexander Stamboliyski, Professor Vasil Zlatarski, Academician Alexandar Todorov – Balan, the writers Ivan Vazov and Aleko Konstantinov, the opera singer Hristina Morfova, the poetess Elisaveta Bagryana and others.