Portal:Czech Republic/Selected anniversaries/May

1 May 2004 – The Czech Republic joins the European Union
9 May 1974 – The Prague Metro begins operation
14 May 1855 – The book The Grandmother by Božena Němcová is released
27 May 1942 – An assassination attempt (pictured) on acting Reichsprotektor Reinhardt Heydrich in Prague as part of Operation Anthropoid results in him dying on 4 June – the villages of Lidice and Ležáky are razed to the ground in response
29 May 1975 – Gustáv Husák becomes President of Czechoslovakia, remaining in office until 1989