Wikipedia:Selected anniversaries/May 20
This is a list of selected May 20 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 20: National Day in Cameroon (1972); Independence Day in East Timor (2002)
- 325 – The First Council of Nicaea, the first ecumenical council of the Christian Church, was formally opened in present-day Iznik, Turkey.
- 1293 – Sancho IV, King of Castile and León, established what is now the Complutense University of Madrid, today one of the top public universities in Spain.
- 1570 – The first modern atlas, Theatrum Orbis Terrarum (world map pictured) by cartographer Abraham Ortelius, was issued.
- 1873 – Clothing manufacturer Levi Strauss and tailor Jacob Davis were granted a patent for using copper rivets to strengthen the pockets of denim overalls, paving the way for their business Levi Strauss & Co. to start manufacturing their first line of blue jeans.
- 1927 – By the Treaty of Jeddah, the United Kingdom recognized the sovereignty of King Ibn Saud in the Kingdoms of Hejaz and Nejd, which later merged to become Saudi Arabia.
- 2002 – East Timor became the first new sovereign state of the twenty-first century after Indonesia relinquished control of the territory.