The storming of the halls of Congress by a mob of President Donald Trump's supporters marks the latest episode of violence to darken the US Capitol in a history dating back to a British arson attack in Washington during the War of 1812.
With four lives lost on the Capitol grounds - one woman shot by police and three fatalities attributed by authorities to medical emergencies - Wednesday's turmoil appeared to rank as the deadliest incident of violence to unfold in and around the citadel of American democracy in 200 years.
But this week's upheaval also stood out in one other notable respect, its White House origins, said David Meyer, a sociology professor at the University of California, Irvine.
"The Capitol is a magnet for protest, and sometimes it's violent," Meyer, author of "The Politics of Protest: Social Movements in America," told Reuters. "What's really unusual this time is a president of the United States explicitly encouraging people to take up violent means against his political opponents."
The following chronology recounts some of the most notorious acts of violence to flare at the Capitol - shootings, bombings, a knife attack, a beating by cane and even an assassination attempt.
1814 - Invading British forces torched the original Capitol building while it was still under construction, setting bonfires of furniture in the House of Representatives and the original Supreme Court chamber.
1835 - In the first known attempt on a US president's life, a disgruntled house painter tried to shoot Andrew Jackson as he emerged from a funeral in the House chamber. The assailant's two flintlock derringers both misfired, and an enraged Jackson clubbed the would-be assassin with his walking stick before the man was subdued. The suspect was found not guilty by reason of insanity and confined to a mental institution.
1856 - An abolitionist senator, Charles Sumner of Massachusetts, was savagely beaten with a cane by his South Carolina colleague, Preston Brooks, on the Senate floor after delivering a speech criticizing slavery.
1915 - A former Harvard University German language professor used a timing device to detonate three sticks of dynamite in an empty Senate reception room during a holiday recess. The professor, angry that American financiers were aiding the British against Germany during World War One, then fled to New York, where he shot and slightly injured banker J.P. Morgan. He was subsequently captured and later took his own life in jail.
1954 - A group of four armed Puerto Rican nationalists indiscriminately opened fire on the House floor from the visitors' gallery and unfurled a Puerto Rican flag. Five members of Congress were wounded. The four assailants - three men and a woman - were apprehended and sentenced to lengthy prison terms, which President Jimmy Carter commuted in 1979.
1971 - A bomb planted by the radical antiwar group Weather Underground to protest the US-backed invasion of Laos was detonated in a restroom on the Senate side of the Capitol, causing extensive damage but no casualties.
1983 - A bomb concealed under a bench outside the Senate chamber exploded, blowing the hinges off the door to the office of then-Senate Democratic leader Robert Byrd and damaging a portrait of renowned lawyer-statesman Daniel Webster. No one was hurt. A militant leftist group said it carried out the bombing in retaliation for US military involvement in Lebanon and Grenada.
1998 - An armed man stormed through a US Capitol security checkpoint and opened fire, fatally wounding two police officers, and made his way to the Republican Whip's office of Representative Tom DeLay. A tourist also was injured. The two slain officers became the first private citizens to lie in honour in the Capitol Rotunda.
2001 - United Airlines Flight 93 crashed in a Pennsylvania field after passengers stormed the cockpit to overpower suicide hijackers, whose likely intended target was later determined by investigators to have been the US Capitol.
2013 - A woman who tried to drive through a White House security checkpoint was chased by authorities to the Capitol, where she was shot dead. Her baby daughter was found unharmed in the vehicle.
2021 - Hundreds of pro-Trump supporters stormed the Capitol and occupied the building for hours, ransacking offices, forcing an evacuation of lawmakers and interrupting their certification of the November presidential election. One woman in the mob was shot to death by police in a corridor of the building. Three other people died of medical emergencies on the Capitol grounds during the tumult.