Wikipedia:Selected anniversaries/May 4

This is a list of selected May 4 anniversaries that appear in the "On this day" section of the Main Page. To suggest a new item, in most cases, you can be bold and edit this page. Please read the selected anniversaries guidelines before making your edit. However, if your addition might be controversial or on a day that is or will soon be on the Main Page, please post your suggestion on the talk page instead.

Please note that the events listed on the Main Page are chosen based more on relative article quality and to maintain a mix of topics, not based solely on how important or significant their subjects are. Only four to five events are posted at a time and thus not everything that is "most important and significant" can be listed. In addition, an event is generally not posted this year if it is also the subject of the scheduled featured article or picture of the day.

To report an error when this appears on the Main Page, see Main Page errors. Please remember that this list defers to the supporting articles, so it is best to achieve consensus and make any necessary changes there first.

← May 3	May 5 →

May 4: Remembrance of the Dead in the Netherlands; Greenery Day in Japan

• 1493 – Pope Alexander VI issued the papal bull Inter caetera, establishing a Line of Demarcation dividing the New World between Spain and Portugal.

• 1855 – American adventurer William Walker (pictured) and a group of mercenaries sailed from San Francisco to conquer Nicaragua.

• 1886 – An unknown assailant threw a bomb into a crowd of police, turning a peaceful labor rally in Chicago into the Haymarket massacre, resulting in the deaths of seven police officers and an unknown number of civilians.

• 1942 – World War II: The Imperial Japanese Navy engaged Allied naval forces at the Battle of the Coral Sea, the first fleet action in which aircraft carriers engaged each other, and the first naval battle in history in which neither side's ships sighted or fired directly upon the other.

• 1979 – Margaret Thatcher became the first female Prime Minister of the United Kingdom.

• 1990 – The Supreme Soviet of the Latvian SSR declared the restoration of independence of Latvia, stating that the Molotov-Ribbentrop Pact and the Soviet occupation of Latvia in 1940 were illegal.

More anniversaries:

• May 3
• May 4
• May 5