April 13th is the 103rd day of the year (104th in leap years) in the Gregorian calendar. There are 262 days remaining until the end of the year. This date is slightly more likely to fall on a Monday, Wednesday or Friday (58 in 400 years each) than on Saturday or Sunday (57), and slightly less likely to occur on a Tuesday or Thursday (56).
1111 – Henry V, the last ruler of the Salian dynasty, was crowned Holy Roman Emperor.
1829 – The Roman Catholic Relief Act was granted royal assent, removing the most substantial restrictions on Catholics in the United Kingdom.
1943 – World War II: German news announced the discovery of a mass grave in Katyn, Russia, of Polish prisoners of war killed by Soviet forces, causing a diplomatic rift between the Polish government-in-exile and the USSR.
1958 – In the midst of the Cold War, American pianist Van Cliburn won the inaugural International Tchaikovsky Competition in Moscow.
1984 – Indian forces launched Operation Meghdoot, a preemptive attack on the disputed Siachen Glacier region of Kashmir, triggering a military conflict with Pakistan.
Paul Sorvino turns 79
Al Green turns 72
Ron Perlman turns 68
Rick Schroder turns 48
Allison Williams turns 30