On this day — May 20

Russia claims full control of the Ukrainian city of Mariupol after a nearly three-month siege.

The base units are redefined, making the international prototype of the kilogram obsolete.

killing 24 people and injuring 377 others.

the first woman to hold this post.

killing 99.

formally ending 23 years of Indonesian rule and three years of provisional UN administration (Portugal itself is the former colonizer of East Timor until 1976).

Evans against a law that would have prevented any city, town or county in the state of Colorado from taking any legislative, executive, or judicial action to protect the rights of gays and lesbians.

setting the scene for the Tiananmen Square massacre.

begins broadcasting to Cuba.

A car bomb planted by UMkhonto we Sizwe explodes on Church Street in South Africa's capital, Pretoria, killing 19 people and injuring 217 others.

the population rejects, with 60% of the vote, a government proposal to move towards independence from Canada.