January 30.
Soon I'll have to ask the mods to rename this thread "This (or a very recent) day in history".
Anyway, January 30th is a very, very busy day in history indeed.
1649. Charles I, King of England, is beheaded. Charles I, an advent believer in the Divine Right of Kings, precipitated his downfall by, among other things, marrying a Catholic, seemingly trying to bring England closer to Roman Catholicism, engaging in religious disputes with the Scots, and most importantly seeking to augment his own power at the expense of Parliament. As a result, civil war erupted, Charles lost, and was executed for treason. Oliver Cromwell was appointed Lord Protector of England. By 1660, however, after the death of Cromwell (more on this below), and the restoration of the monarchy under Charles' son, Charles II, Charles I was canonized by the Church of England.
1661. On this date, Oliver Cromwell, the former Lord Protector of England, is ritually beheaded on the anniversary of the execution of Charles I. I say "ritually", because his body was exhumed due to his already having been dead for nearly two years in order for the rather gruesome at that point head to be separated from the rest of the body. What was left of his body was then hanged in chains at Tyburn, London, where many English executions took place. His body was eventually thrown into a pit. His head, however, was mounted on a pole outside Westminster Hall for nearly 25 years, until 1685, after which, it went through many hands over the next several hundred years (including being bought and sold) until eventually interred in 1960. It must have been a heck of a conversation piece...
1835. In the first assassination attempt against a US President, Richard Lawrence attempts to shoot President Andrew Jackson. He was clearly mentally ill, believing that he was Richard III, King of England, and once he was paid a substantial sum owed to him by the US government (which Jackson was improperly withholding from him), he would be able to go and claim the throne.
1862. First US ironclad, the Monitor, is launched. It and its enemy sister-ship, the Merrimack, would revolutionize naval warfare.
1933. Adolf Hitler is sworn in as Chancellor of Germany. In retrospect many believe this was not a particularly good idea.
1968. The Tet Offensive begins in Vietnam. See prior post regarding the Battle of Khe Sanh. The Tet Offensive was the largest attack by the Vietcong during the war, with over 80,000 troops attacking in over 100 South Vietnamese cities and towns. While it had an unquestionably disastrous military result on Vietnamese forces -- indeed the Vietcong were largely wiped out as a result -- the attack had a massive propaganda value, convincing the American public that they had been misled about American success to date during the war, and the chances of winning the war.