Mexico formally gained independence from Spain after a protracted war that lasted from 1810 to 1821 and is now known as the Mexican War of Independence. However, Spanish power in the region had been declining for centuries, which was why Spain, unlike most other European powers, lost almost all of its overseas colonies over the course of the nineteenth century, while such countries as France and Great Britain not only held onto their existing possessions (with the notable exception of the thirteen American colonies that formed the United States after separating from Great Britain), but actually gained territory, through, for example, the establishment of the British Raj in India in 1858 (which built upon a century of direct administration of the subcontinent by the East India Company) and the so-called “scramble for Africa” that began in 1870 and reached its high point with the Berlin Conference of 1884. In contrast to these massive gains by other European countries, Spain lost the vast majority of its colonial holdings between 1810, when Argentina became the first Spanish colony in the Americas to form an independent nation, and 1898, when it lost the Philippians, Guam, Puerto Rico, and Cuba in the Spanish-American war.

There are at least two major reasons for this striking difference between Spain and other European colonial powers. The first of these is long-term and the second is short-term. The first, long-term reason is that, because Spain’s empire was, for the most part, established in the sixteenth century (through the conquest of the Aztecs, the Inca, and other indigenous peoples of the Americas), it administered by Spain through an essentially feudal system of government, where land and the labor of indigenous peoples were awarded to local leaders who were loyal to the Spanish monarchy, or to the Catholic church. This is in stark contrast to, say, British rule in India, which was carried out first by a private corporation and then by a modern, bureaucratic civil service organization. Thus, Spanish colonial rule was consistently inefficient, and this system persisted in spite of repeated attempts to reform and modernize it, most notably the “Bourbon Reforms” of the mid-eighteenth century.

The second, more immediate reason for the collapse of the Spanish Empire in the early nineteenth century was the Napoleonic wars in Europe. Napoleon Bonaparte invaded Spain in 1808 and quickly dethroned the Bourbon monarchy. This crisis left the door open for Spain’s American colonies to claim independence, which virtually all did, starting with Argentina in 1810. The Mexican War of Independence, which started that same year, can be said to be a direct continuation of this process. Spain’s hold on its possessions in the Americas was already weak due to poor administration and the relative failure of the Bourbon Reforms (given the massive efforts involved in implementing them and the small results they garnered). The Napoleonic wars provided cover for many of these colonies, including Mexico, to claim formal independence from Spain.

Mexico gained its independence from Spain through a revolutionary war.  This war is generally said to have begun in 1810 and to have ended in 1821.  The Mexican bid for independence was greatly helped by events in Europe.

For a long time, Mexican criollos (people of pure Spanish descent but born in Mexico) had been displeased with the Spanish government.   The Spanish government had treated them poorly, not letting them have the same rights and privileges as Spaniards born in Spain.  In 1808, Napoleon invaded and occupied Spain.  This made Mexicans even more eager to become independent from Spain since their mother country was no longer even controlled by Spaniards.  In 1810, Miguel Hidalgo, a criollo priest, began a rebellion for equality for all Mexicans (including mestizos and Indians) and for independence.  Although Hidalgo was captured and executed, the rebellion continued until it triumphed in 1827 and Mexico was officially independent.