site.btaObservances: April 16

Bulgaria:

- Constitution Day.

On this date in Bulgarian history:

1879: (New Style April 28) In Tarnovo (today's Veliko Tarnovo), Constituent Assembly adopts Constitution of the Principality of Bulgaria (later known as Tarnovo Constitution) (suspended July 2/13, 1881 - September 6/18, 1883, amended May 15, 1893, and July 11, 1911, suspended May 19, 1934, superseded by Constitution of the People's Republic of Bulgaria, December 6, 1947).

1925: Extreme left group of Bulgarian Communist Party militants commit worst ever bombing attack at Sofia's St Nedelya Church, killing 150 people (mostly members of political and military elite) and injuring around 500.