This Day in History: June 27

1542: Juan Rodríguez Cabrillo explores the west coast of North America

On behalf of the Spanish Empire, Juan Rodríguez Cabrillo sets sail from the Mexican port of Navidad to explore the west coast of North America. His expedition would reach as far north as Oregon before he died in January 1543.

1743: King George II leads troops in Battle of Dettingen

During the War of the Austrian Succession, King George II of Britain personally leads troops into the Battle of Dettingen in Bavaria. This would be the last time a British monarch commanded troops in the field.

1950: North Korean troops reach Seoul, US intervenes in Korean conflict

North Korean troops reach Seoul, prompting the United Nations to ask its members to aid South Korea. US President Harry Truman orders the US Air Force and Navy to intervene in the conflict, which would become known as the Korean War.

1954: First nuclear power plant opens in Russia

The world's first nuclear power plant, located in Obninsk near Moscow, is activated. The reactor would remain in operation for 48 years. Today, there are approximately 400 nuclear power plants worldwide, although the technology remains controversial due to the unsolved long-term storage of nuclear waste.

1986: US intervention in Nicaragua declared illegal

The International Court of Justice condemns the US paramilitary campaign to overthrow the left-wing Sandinista government of Nicaragua, which had initiated programs to redistribute wealth and improve education. The US intervention, which began in the 1980s, was declared illegal by the court.

1991: Yugoslav troops invade Slovenia

Following Slovenia's declaration of independence, Yugoslav troops invade the country, marking the beginning of the Ten-Day War. This was the first of the Yugoslav Wars, a series of ethnic conflicts that led to the break-up of Yugoslavia and resulted in at least 140,000 deaths.