site.btaObservances: November 21

On this date in Bulgarian history:

1912: In Battle of Kaliakra, Bulgarian torpedo boat Drazki torpedoes Ottoman protected cruiser Hamidiye during First Balkan War.

1967: Diplomatic relations established with Singapore.

1999: US President Bill Clinton pays official visit to Bulgaria (until November 23).

2002: At NATO's Summit in Prague, Bulgaria, Romania, Slovenia, Slovakia, Lithuania, Latvia and Estonia are invited to open negotiations on accession to Alliance.

2004: Turkish-Bulgarian Culture and Information Centre opens in Istanbul.