The 19th (nineteenth) century began on January 1, 1801, and ended on December 31, 1900. The term is often used to refer to the 1800s, the century between January 1, 1800 and December 31, 1899. The 19th century was the ninth century of the 2nd millennium.
The 19th century saw large amounts of social change; slavery was abolished, and the First and Second Industrial Revolutions (which also overlap with the 18th and 20th centuries, respectively) led to massive urbanization and much higher levels of productivity, profit and prosperity. The Islamic gunpowder empires were formally dissolved and European imperialism brought much of South Asia, Southeast Asia and almost all of Africa under colonial rule.
It was marked by the collapse of the Spanish, Zulu Kingdom, First French, Holy Roman and Mughal empires. This paved the way for the growing influence of the British Empire, the Russian Empire, the United States, the German Empire (essentially replacing the Holy Roman Empire), the Second French Empire, the Kingdom of Italy and Meiji Japan, with the British boasting unchallenged dominance after 1815. After the defeat of the French Empire, and its Indian allies in the Napoleonic Wars, the British and Russian empires expanded greatly, becoming the world's leading powers. The Russian Empire expanded in the Caucasus, central and far eastern Asia. The Ottoman Empire went through a period of westernization and reform known as the Tanzimat, vastly increasing their control over their core territories in Anatolia and the Near East. Despite this, the sick man of Europe remained in a period of decline, losing territory in the Balkans, Egypt, and North Africa.
The remaining powers in the Indian subcontinent such as the Kingdom of Mysore and its French allies, Nawabs of Bengal, Maratha Empire, Sikh Empire and the princely states of the Nizam of Hyderabad, suffered a massive decline, and their dissatisfaction with British East India Company's rule led to the Indian Rebellion of 1857, marking its dissolution, however, it was later ruled directly by the British Crown through the establishment of the British Raj.
The British Empire grew rapidly in the first half of the century, especially with the expansion of vast territories in Canada, Australia, South Africa and heavily populated India, and in the last two decades of the century in Africa. By the end of the century, the British Empire controlled a fifth of the world's land and one-quarter of the world's population. During the post-Napoleonic era, it enforced what became known as the Pax Britannica, which had ushered in unprecedented globalization and economic integration on a massive scale.