January 5–Robert-François Damiens makes an unsuccessful assassination attempt on Louis XV of France, who is slightly wounded by the knife attack. Damiens is executed on March 28.
February 2– At Versailles in France, representatives of the Russian Empire and the Austrian Empire enter into an alliance against Prussia, with each nation pledging 80,000 troops. Other clauses to the treaty, not disclosed to the public, commit Austria to pay Russia one million rubles per year during the war to pay for the expenses of 24,000 of the Russian troops, and two million rubles upon the conquest of Silesia (a Prussian province that had been seized from Austria in 1746).
February 3– French artist Robert Picault begins the rescue of the frescoes at the King's Chamber of the Palace of Fontainebleau before architect Ange-Jacques Gabrel begins renovations.
February 5– The Nawab of Bengal, Siraj ud-Daulah, leads an attempt to retake Calcutta from the British. With just 1,900 soldiers and sailors, but superior cannon power, General Robert Clive forces the Nawab's much larger force into a retreat. The British sustain 194 casualties, but the Bengalis suffer 1,300.
February 9– The Nawab and General Clive sign the Treaty of Alinagar, with Bengal compensating the British East India Company for its losses and pledging respect for British control of India.
March 14– British Royal Navy Admiral John Byng is executed by firing squad on board the ship HMS Monarch in the Solent after his court martial conviction for failing in the Battle of Minorca (1756) to save British troops who had been besieged by a numerically superior French force in the Siege of Fort St Philip. General Edward Cornwallis, the ranking British Army officer at the battle, is exonerated of charges of dereliction of duty, but his career is ruined. Byng's execution is the origin of the phrase "In this country, it is wise to kill an admiral from time to time to encourage the others", coined by Voltaire in his novel Candide.
March 21–Sweden signs an alliance treaty with France and Austria in the multinational effort to remove King Frederick the Great, even though Queen Consort Ulrika of Sweden is Frederick's sister. Sweden agrees to contribute 25,000 troops to the French and Austrian force.
March 28–Robert-François Damiens is tortured, then dismembered and his remains burned in public for his January 5 assassination attempt on King Louis XV of France, the last person in France to suffer this punishment.
In the wake of public unrest in France, the King's Council issues a decree that bars anyone from writing or printing anything that would tend toward émouvoir les esprits (stir up popular sentiment) against the government, with violations punishable by death.
April 29– Inside the house at Stratford-upon-Avon in England known as Shakespeare's Birthplace, a bricklayer, identified only as "Mosely", re-tiling the roof, discovers a supposed pro-Catholic testament of John Shakespeare, father of William Shakespeare, more than 150 years after the elder's death. The finding starts "what remains one of the most controversial topics in Shakespeare studies" because of disagreements over its authenticity and date.
May 1–France and Austria sign a second Treaty of Versailles, committing France to sending an additional 105,000 troops to the war against Prussia, and to pay expenses to Austria at the rate of 12 million florins annually.
The 1755 rebellion against the Chinese Empire by Mongolian Oirat Prince Amursana is met by a Chinese army of 10,000 attackers against Amursana's 2,500 man force at their capital at Bor Tal. The rebels hold out until July 17.
July–September
July 2– The Duke of Newcastle is asked to form a new government of Great Britain and fills the office of Prime Minister of Great Britain, after his forced resignation eight months earlier. Pitt is recalled to conduct Britain's foreign and military affairs and given greater control.
July 17–Amursana's Mongolian rebellion against the Chinese Empire is crushed after a battle of 17 days, and the survivors flee to Russia, where Amursana unsuccessfully seeks Russian aid.
September 6– The life of Najib ad-Dawlah is spared by Raghunathrao upon the intercession of General Malhar Rao Holkar. Najib and his family are permitted to leave the Fort along with most of their property, and the Emperor Alamgir II is restored to the Mughal throne as a nominal ruler.
September 7–Seven Years' War: Battle of Moys– A Prussian army (some 13,000 men) under Hans von Winterfeldt fights an Austrian army of double their size. The Prussians are defeated near Moys and von Winterfeldt is killed.
September 13–Pomeranian War: A column of troops from Sweden begins the surprise invasion of Prussia, setting up a pontoon bridge across the Peene River that marks the boundary between Swedish Pomerania and northern Prussia. After crossing at Loitz in the early morning hours, the troops march 10 kilometres (6.2mi) and begin the occupation of the undefended Prussian town of Demmin. Hours later, another Swedish infantry regiment charges across the border into the Prussian town of Anklam, where the city gate had been left open.
October 4– Bearing British flags, two French privateers sail up the Gambia River and attempt to capture the British fort on James Island, but their ruse is discovered the next day before they can stage their attack. The two ships are captured by the Royal Navy after retreating
October 14– Of the 478 people arrested, and 442 (including 50 women and young boys) convicted, for their roles in the Porto riot in February, 13 men and one woman are hanged; afterwards, their bodies are then quartered, and the severed limbs are publicly displayed on spikes. Another 49 men and 10 women are exiled to Portuguese colonies in Africa and India, and the other convicts are either flogged, imprisoned, or pressed into service rowing galley ships.
October 16–Seven Years' War: Raid on Berlin– Hungarian raiders (3,400 horseman) under Count András Hadik plunder Berlin. He demands that the city council pay a ransom of 200,000 thalers and a dozen pairs of gloves for Empress Maria Theresa. The Hungarians leave the Prussian capital after they received messages about a Prussian relief force under Prince Dietrich von Anhalt-Dessau, marching towards Berlin.
October 24 (10 Safar 1171 A.H.) –1757 Hajj caravan raid: Bedouin warriors of the Bani Sakher confederacy conduct a massive assault against a caravan of thousands of Muslim travelers who are on their way back to Damascus after the Hajj, the pilgrimage to Mecca. The attack, made at Hallat Ammar after the group has been resupplied at Tabuk, leads to the annihilation of 20,000 of the pilgrims. Those who are not killed outright die later in the desert from thirst and starvation. According to one Arabic source, the largest attack takes place on October 24.
December 5–Seven Years' War: Battle of Leuthen– Frederick defeats Prince Charles's Austrian army, in what is generally considered the Prussian king's greatest tactical victory.
December 24– The Pratt-Yorke opinion distinguishes British overseas territories acquired by conquest from those acquired by private treaty: while the Crown of Great Britain enjoys sovereignty over both, only the property of the former is vested in the Crown.
Robert Wood publishes The ruins of Balbec, otherwise Heliopolis in Coelosyria in English and French, making the ancient city of Baalbek, Syria known to the West.