On July 31

The largest power outage in history occurred across 22 Indian states, affecting more than 620 million people, or about 9 percent of the world's population.

The Troubles: Operation Banner, the British Armed Forces' operation in Northern Ireland, ended after 38 years with a military stalemate and ceasefire.

Following intestinal surgery, Fidel Castro provisionally transferred the duties of the Cuban presidency to his brother Raúl.

Hamas detonated a bomb at the Mount Scopus campus of the Hebrew University of Jerusalem, killing nine students and injuring about 100 more.

Three years after being hit by a mudslide, the Ten Thousand Buddhas Monastery (pagoda pictured) in Hong Kong fully reopened.

Soviet Special Purpose Police Unit troops killed seven Lithuanian customs officials in Medininkai in the most serious attack of their campaign against Lithuanian border posts.

The Troubles: In a botched paramilitary attack, three members of the popular Miami Showband and two Ulster Volunteer Force gunmen were killed in County Down, Northern Ireland.

The Troubles: Hours after the British Army's Operation Motorman brought an end to the self-declared autonomous area of Free Derry (Free Derry Corner pictured) in Northern Ireland, three car bombs exploded in the village of Claudy.

The pleasure cruiser MV Darlwyne disappeared off the coast of Cornwall with the loss of all 31 people aboard.

The space probe Ranger 7 captured thousands of close-up photographs of the Moon over its final minutes of flight and transmitted them to Earth before crashing on the lunar surface.

A team of Italian climbers became the first to reach the summit of K2, the world's second-highest mountain.

The Holocaust: Under instructions from Adolf Hitler, Hermann Göring authorised SS officer Reinhard Heydrich to handle preparations for "the Final Solution of the Jewish question".

A private senator's bill by Herbert Payne to introduce compulsory voting in Australia became law.

First World War: The Battle of Passchendaele began near Ypres, Belgium, with the Allies aiming to force German troops to withdraw from the Channel Ports.

Patrick Francis Healy was inaugurated as president of Georgetown University, becoming the first African-American president of a predominantly white university in the United States.

The Second Continental Congress passed a resolution commissioning the Marquis de Lafayette (pictured) as a major general in the American revolutionary forces.

The Second Anglo-Dutch War ended with the signing of the Treaty of Breda.

Sergius IV became the 142nd pope, succeeding John XVIII.