The siege of Yorktown, also known as the Battle of Yorktown, the surrender at Yorktown, or the German battle (from the presence of Germans in all three armies), beginning on September 28, 1781, and ending on October 19, 1781, at Yorktown, Virginia, was a decisive victory by a combined force of the American Continental Army troops led by General George Washington and Gilbert du Motier, Marquis de Lafayette, and French Army troops led by Comte de Rochambeau over British Army troops commanded by British peer and Lieutenant General Charles Cornwallis. The culmination of the Yorktown campaign, the siege proved to be the last major land battle of the American Revolutionary War in the North American region, as the surrender by Cornwallis, and the capture of both him and his army, prompted the British government to negotiate an end to the conflict.In 1780, about 5,500 French soldiers landed in Rhode Island to help their American allies fight the British troops who controlled New York City. Following the arrival of dispatches from France that included the possibility of support from the French West Indies fleet of the Comte de Grasse, disagreements arose between Washington and Rochambeau on whether to ask de Grasse for assistance in besieging New York or in military operations against a British army in Virginia. On the advice of Rochambeau, de Grasse informed them of his intent to sail to the Chesapeake Bay, where Cornwallis had taken command of the army. Cornwallis, at first given confusing orders by his superior officer, Henry Clinton, was eventually ordered to build a defensible deep-water port, which he began to do in Yorktown. Cornwallis' movements in Virginia were shadowed by a Continental Army force led by the Marquis de Lafayette.

The French and American armies united north of New York City during the summer of 1781. When word of de Grasse's decision arrived, both armies began moving south toward Virginia, engaging in tactics of deception to lead the British to believe a siege of New York was planned. De Grasse sailed from the West Indies and arrived at the Chesapeake Bay at the end of August, bringing additional troops and creating a naval blockade of Yorktown. He was transporting 500,000 silver pesos collected from the citizens of Havana, Cuba, to fund supplies for the siege and payroll for the Continental Army. While in Santo Domingo, de Grasse met with Francisco Saavedra de Sangronis, an agent of Carlos III of Spain. De Grasse had planned to leave several of his warships in Santo Domingo. Saavedra promised the assistance of the Spanish navy to protect the French merchant fleet, enabling de Grasse to sail north with all of his warships. In the beginning of September, he defeated a British fleet led by Sir Thomas Graves that came to relieve Cornwallis at the Battle of the Chesapeake. As a result of this victory, de Grasse blocked any reinforcement or escape by sea for Cornwallis and also disembarked the heavy siege guns required by the allied land forces. By late September, Washington and Rochambeau arrived, and the army and naval forces completely surrounded Cornwallis.

After initial preparations, the Americans and French built their first parallel and began the bombardment. With the British defense weakened, on October 14, 1781, Washington sent two columns to attack the last major remaining British outer defenses. A French column under Wilhelm of the Palatinate-Zweibrcken took Redoubt No. 9 and an American column under Alexander Hamilton took Redoubt No. 10. With these defenses taken, the allies were able to finish their second parallel. With the Franco-American artillery closer and its bombardment more intense than ever, the British position began to deteriorate rapidly. Cornwallis asked for capitulation terms on October 17. After two days of negotiation, the surrender ceremony occurred on October 19; Cornwallis was absent from the ceremony. With the capture of more than 7,000 British soldiers, negotiations between the United States and Great Britain began, resulting in the Treaty of Paris of 1783.

The battlegrounds are preserved and interpreted today as part of Colonial National Historical Park.

Charles Cornwallis, 1st Marquess Cornwallis, (31 December 1738 – 5 October 1805), styled Viscount Brome between 1753 and 1762 and known as the Earl Cornwallis between 1762 and 1792, was a British Army general and official. In the United States and the United Kingdom he is best remembered as one of the leading British generals in the American War of Independence. His surrender in 1781 to a combined American and French force at the siege of Yorktown ended significant hostilities in North America. He later served as a civil and military governor in Ireland, where he helped bring about the Act of Union; and in India, where he helped enact the Cornwallis Code and the Permanent Settlement.

Born into an aristocratic family and educated at Eton and Cambridge, Cornwallis joined the army in 1757, seeing action in the Seven Years' War. Upon his father's death in 1762 he became Earl Cornwallis and entered the House of Lords. From 1766 until 1805 he was Colonel of the 33rd Regiment of Foot. He next saw military action in 1776 in the American War of Independence. Active in the advance forces of many campaigns, in 1780 he inflicted an embarrassing defeat on the American army at the Battle of Camden. He also commanded British forces in the March 1781 Pyrrhic victory at Guilford Court House. Cornwallis surrendered his army at Yorktown in October 1781 after an extended campaign through the Southern states, marked by disagreements between him and his superior, General Sir Henry Clinton.

Despite this defeat, Cornwallis retained the confidence of successive British governments and continued to enjoy an active career. Knighted in 1786, he was in that year appointed to be Governor-General and commander-in-chief in India. There he enacted numerous significant reforms within the East India Company and its territories, including the Cornwallis Code, part of which implemented important land taxation reforms known as the Permanent Settlement. From 1789 to 1792 he led British and Company forces in the Third Anglo-Mysore War to defeat the Mysorean ruler Tipu Sultan.

Returning to Britain in 1794, Cornwallis was given the post of Master-General of the Ordnance. In 1798 he was appointed Lord Lieutenant and Commander-in-chief of Ireland, where he oversaw the response to the 1798 Irish Rebellion, including a French invasion of Ireland, and was instrumental in bringing about the Union of Great Britain and Ireland. Following his Irish service, Cornwallis was the chief British signatory to the 1802 Treaty of Amiens and was reappointed to India in 1805. He died in India not long after his arrival.