January 27 is the 27th day of the year in the Gregorian calendar. There are 338 days remaining until the end of the year.
AD 98 – Trajan succeeds his adoptive father Nerva as Roman emperor; under his rule the Roman Empire would reach its maximum extent.
45 – The co-emperors Stephen and Constantine are overthrown and forced to become monk by Constantine VII,[2] who becomes sole emperor of the Byzantine Empire.
1186 – Henry VI, the son and heir of the Holy Roman Emperor Frederick I, marries Constance of Sicily.
1302 – Dante Alighieri is exiled from Florence.
1343 – Pope Clement VI issues the papal bull Unigenitus to justify the power of the pope and the use of indulgences. Nearly 200 years later, Martin Luther would protest this.
1606 – Gunpowder Plot: The trial of Guy Fawkes and other conspirators begins, ending with their execution on January 31.
1695 – Mustafa II becomes the Ottoman sultan and Caliph of Islam in Istanbul on the death of Ahmed II. Mustafa rules until his abdication in 1703.
1776 – American Revolutionary War: Henry Knox's "noble train of artillery" arrives in Cambridge, Massachusetts.
1785 – The University of Georgia is founded, the first public university in the United States.
1820 – A Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Petrovich Lazarev discovers the Antarctic continent, approaching the Antarctic coast.
1825 – The U.S. Congress approves Indian Territory (in what is present-day Oklahoma), clearing the way for forced relocation of the Eastern Indians on the "Trail of Tears".
1868 – Boshin War: The Battle of Toba–Fushimi between forces of the Tokugawa shogunate and pro-Imperial factions begins, which will end in defeat for the shogunate, and is a pivotal point in the Meiji Restoration.
1869 – Boshin War: Tokugawa rebels establish the Ezo Republic in Hokkaidō.
1880 – Thomas Edison receives the patent on the incandescent lamp.
1916 – World War I: The British government passed a legislation that introduced conscription in the United Kingdom.
1918 – Beginning of the Finnish Civil War.
1927 – Ibn Saud takes the title of King of Nejd.
1939 – First flight of the Lockheed P-38 Lightning.
1943 – World War II: The Eighth Air Force sorties ninety-one B-17s and B-24s to attack the U-boat construction yards at Wilhelmshaven, Germany. This was the first American bombing attack on Germany.
1944 – World War II: The 900-day Siege of Leningrad is lifted.
1945 – World War II: The Soviet 322nd Rifle Division liberates the remaining inmates of Auschwitz-Birkenau.
1951 – Nuclear testing at the Nevada Test Site begins with Operation Ranger.
1961 – The Soviet submarine S-80 sinks when its snorkel malfunctions, flooding the boat.
1967 – Apollo program: Astronauts Gus Grissom, Ed White and Roger Chaffee are killed in a fire during a test of their Apollo 1 spacecraft at the Kennedy Space Center, Florida.
1967 – Cold War: The Soviet Union, the United States, and the United Kingdom sign the Outer Space Treaty in Washington, D.C., banning deployment of nuclear weapons in space, and limiting use of the Moon and other celestial bodies to peaceful purposes.
1973 – The Paris Peace Accords officially end the Vietnam War. Colonel William Nolde is killed in action becoming the conflict's last recorded American combat casualty.
1980 – Through cooperation between the U.S. and Canadian governments, six American diplomats secretly escape hostilities in Iran in the culmination of the Canadian Caper.
1983 – The pilot shaft of the Seikan Tunnel, the world's longest sub-aqueous tunnel (53.85 km) between the Japanese islands of Honshū and Hokkaidō, breaks through.
1996 – In a military coup, Colonel Ibrahim Baré Maïnassara deposes the first democratically elected president of Niger, Mahamane Ousmane.
1996 – Germany first observes the International Holocaust Remembrance Day.
2002 – An explosion at a military storage facility in Lagos, Nigeria, kills at least 1,100 people and displaces over 20,000 others.
2003 – The first selections for the National Recording Registry are announced by the Library of Congress.
2010 – The 2009 Honduran constitutional crisis ends when Porfirio Lobo Sosa becomes the new President of Honduras.
2011 – Arab Spring: The Yemeni Revolution begins as over 16,000 protestors demonstrate in Sana'a.
2013 – Two hundred and forty-two people die in a nightclub fire in the Brazilian city of Santa Maria, Rio Grande do Sul.
