site.btaObservances: August 20

The world:

- National Day of Hungary (Feast Day of King St Stephen I).

On this date in Bulgarian history:

917: Bulgarian Tsar Simeon I defeats Byzantine army at mouth of River Achelous in huge battle involving more than 120,000 soldiers. In aftermath of battle, Bulgarian State acquires complete military and political hegemony in Southeastern Europe.

1887: Prime Minister Stefan Stambolov forms cabinet (in office until May 19, 1894).

1935: Bulgarian Georgi Dimitrov is elected Secretary General of Communist International (Comintern) (until organisation's dissolution on June 10, 1943).

1988: Bulgarian athlete Yordanka Donkova sets women's 100 m hurdles world record,12.21 sec, at event in Stara Zagora (Southeastern Bulgaria) (broken by Kendra Harrison of US in London, July 22, 2016).

2004: 23.5-carat gold, 672 g life-size mask of Thracian King Teres I (d. 445 BC) is unearthed during archaeological excavations near Shipka, Central Bulgaria.