site.btaObservances: June 4

The world:

- International Day of Innocent Children Victims of Aggression;
- Independence Day in Tonga (1970).

On this date in Bulgarian history:

1891: Princess Clementine Hospital (today's Hospital No. 5) is unveiled in Sofia.

1957: The Committee on Peaceful Uses of Atomic Energy (today's Nuclear Regulatory Agency) is established.

1998: The National Health Insurance Fund is established as Parliament passes the Health Insurance Act.

2013: Near Popovo, archaeologists discover a unique, 12-centimeter-long bronze oil lamp in a 4th-century archaeological layer at the late Roman fortress Kovachevsko Kale.

2016: Bulgaria breaks the Guinness World Record for the longest line of Ford vehicle, a 20-km-long convoy of 1,527 cars in Sofia.

2019: Bulgarian company SIN Cars presents a prototype of the first Bulgaria-made electric car, L CITY.