June 26 is Flag Day in Romania, and it commemorates the first official adoption of the Romanian tricolour as a national flag by Wallachian revolutionaries in 1848. The inscription in the centre of the flag read “Justice” in Wallachian and “Brotherhood” in Moldavian.
The tricolour was actually already in use before that date; it had been used on military flags since 1834. And it continued being used even after the revolution was quashed. A similar flag was adopted by the United Romanian Principalities in 1859, and it eventually evolved into the plain vertical tricolour we know today.