The French invasion of 1808 that made Joseph Bonaparte King led to the outbreak of the Guerra de la Independencia Española or War of Independence in May. Zaragoza was largely destroyed in February 1809 during the Second Siege of Zaragoza, bringing a halt to its economic development. The 1812 Constitution proposed a number of reforms, including the creation of provincial territories and dividing Aragon into the four provinces of Calatayud, Teruel, Soria and Guadalajara. However, these reforms were delayed by Ferdinand VII’s refusal to accept the constitution and finally implemented in 1822 during the 1820–23 Trienio Liberal. When Ferdinand was restored by French Bourbon forces in 1823, he abolished the Constitution along with the provincial reforms. When he died in 1833, the provincial division of 1833 divided Aragon into its current three provinces.

Throughout the 19th century, Aragon was a stronghold of the Carlists, who offered to restore the fueros and other rights associated with the former Kingdom of Aragon. This period saw a massive exodus from the countryside into the larger cities of Aragon such as Huesca, Zaragoza, Teruel or Calatayud and other nearby regions, such as Catalonia or Madrid.

The history of Aragon in the first half of the 20th century was similar to that of the rest of Spain; the building of infrastructure and reforms made by Miguel Primo de Rivera led to a brief economic boom, with new civil and individual liberties during the Second Spanish Republic. In June 1936, a draft Statute of Autonomy of Aragon was presented to the Cortes Generales but the outbreak of the Spanish Civil War prevented the development of this autonomist project.