From its ninth-century origins as a ceremony dedicated to remembering saints and the dead, Halloween has evolved—or, depending on one's perspective, devolved—into a largely secular holiday associated more with crunchy Candy Corn and costumes reflecting the increasing vacuousness of Western popular culture than with solemn reverence for the departed. But beware: an eerie number of frightening historical events have occurred on Halloweens past, events that resulted both in tremendous levels of bloodletting and far-reaching transformations of the world’s geopolitical landscape. Below is a list of the top five scariest historical events that happened on October 31. Read on, if you dare….

#5 On the night of October 31, 1954, the indigenous Algerian Front de Libération Nationale, or FLN, launched attacks on French government assets in Algeria, igniting the Algerian War of Independence, a brutal liberation struggle characterized by massive human rights abuses, including torture by both sides. The conflict divided France politically and cost numerous French prime ministers their jobs. It also brought down France’s Fourth Republic, which involved riots, revolts, and even rebellion by a section of the country’s army. After nearly seven-and-a-half years, over 40,000 terrorist attacks, and hundreds of thousands of battle deaths, the French withdrew in June 1962. The following month, Algeria, which France had since 1848 considered to be an integral part of French territory, declared independence, effectively ending the second French colonial empire.

#4 After the March on Rome from October 22-29, Benito Mussolini was sworn in as Italy’s prime minister on October 31, 1922, fulfilling his threat that "either the government will be given to us or we shall seize it by marching on Rome." Before long, Il Duce turned Italy into a police state. In what was quickly revealed to be a hopeless attempt to resurrect the Holy Roman Empire, Mussolini presided over Italy’s invasion and occupation of Ethiopia in the Second Italo-Ethiopian War, during which Italy employed chemical warfare agents on a massive scale; the conflict led to approximately 20,000 battle deaths. After the demise of Italy’s colonial presence in Africa, Mussolini’s alliance with the Nazis effectively put Italy in the position of being a puppet state subordinate to Germany. The result was Germany’s brutal occupation of Italy and the Allies’ invasion in 1943, which, in making Italy a key battleground during World War II, also devastated the country. In the end, despite supposedly making the “trains run on time”, Mussolini’s Italy was characterized by rampant corruption, dictatorship, racist laws and, finally, utter ruin.

#3 Turkey joined the Central Powers on October 31, 1914, which would eventually result in the dissolution of the Ottoman Empire and the drawing of conflict-prone national borders across the Middle East. On November 2, Russia declared war against Turkey; France and Great Britain followed suit on November 5. Although the Ottomans were eventually defeated, the road to victory was hard, bloody, and horrific; the Gallipoli Campaign, generally considered a defeat for the Allies, was particularly costly. Eighteen months after jointly declaring war, France and Britain, with Russia’s assent, signed the Sykes-Picot Agreement, spelling out each party’s proposed sphere of influence in a post-Ottoman Middle East. After Russia’s revolutionary Bolshevik government was subsequently denied any claims to Ottoman territory, it published the text of the agreement in November 1917, exposing French and British imperial designs on the region. The eventual implementation of Sykes-Picot resulted in the drawing of national borders that in many cases failed to correspond to demographic realities on the ground, thereby sowing the seeds of many future conflicts in the Middle East, a phenomenon that still haunts the region to this day. Nonetheless, the demise of the “sick man of Europe” ushered in a period of French and particularly British regional dominance that lasted for over four decades.

#2 However, everything started to come crashing down for Great Britain and France when they entered the Suez Crisis, one of history’s most infamous foreign policy misadventures, on October 31, 1956. In collusion with Britain and France, both reeling from Egyptian President Gamal Abdel Nasser’s recent nationalization of the Suez Canal, Israel invaded Egypt's Sinai Peninsula on October 29, 1956, after which Britain and France called on Israel and Egypt to cease all hostilities, withdraw ten miles from the Suez Canal, and allow Anglo-French forces to occupy the Canal Zone. When Nasser followed the Anglo-French-Israeli script by refusing these conditions on October 31, Britain and France intervened militarily against Egypt the same day, which also happened to be just days before the U.S. presidential election, infuriating President Eisenhower. The Soviet Union, which almost entered the conflict, stood by the US at the United Nations to condemn the British and French actions, which compelled British Prime Minister Anthony Eden to declare a ceasefire. At the end of the day, Britain and France, neither of which accomplished their military objectives in the campaign, during which over 2,100 men lost their lives, were discredited in the region, ushering the era of American preeminence in the Middle East.

#1 Characterized by tremendous turmoil and bloodletting, the Protestant Reformation was sparked on October 31, 1517, when Martin Luther nailed his Ninety-Five Theses to the Wittenberg church door. In 1648, the Reformation concluded with the Peace of Westphalia, a series of peace treaties signed between the major European powers that ended the Thirty Years’ War, among the most destructive of Europe’s many conflagrations. Beyond ending Europe’s wars of religion, the peace treaties are also widely credited with establishing the principle of sovereignty, the fundamental basis for the modern international system of nation-states, which fundamentally redefined Europe’s age-old political fault lines.

Image: Composite of Flickr/Kevin Gill. CC BY-SA 2.0, and Wikimedia Commons/Andre Koehne, CC BY-SA 3.0.