section_path: History/Capital of the Liberal State
section_name: Capital of the Liberal State
paragraph_text: Capital of the Liberal State
  
  The city was invaded on 24 May 1823 by a French army—the so-called Hundred Thousand Sons of Saint Louis —called to intervene to restore the absolutism of Ferdinand that the latter had been deprived from during the 1820–1823 trienio liberal. Unlike other European capitals, during the first half of the 19th century the only noticeable bourgeois elements in Madrid (that experienced a delay in its industrial development up to that point) were merchants. The University of Alcalá de Henares was relocated to Madrid in 1836, becoming the Central University.
  
  The economy of the city further modernized during the second half of the 19th century, consolidating its status as a service and financial centre. New industries were mostly focused in book publishing, construction and low-tech sectors. The introduction of railway transport greatly helped Madrid's economic prowess, and led to changes in consumption patterns (such as the substitution of salted fish for fresh fish from the Spanish coasts) as well as further strengthening the city's role as a logistics node in the country's distribution network. Electric lighting in the streets was introduced in the 1890s.
  
  During the first third of the 20th century the population nearly doubled, reaching more than 850,000 inhabitants. New suburbs such as Las Ventas, Tetuán and El Carmen became the homes of the influx of workers, while Ensanche became a middle-class neighbourhood of Madrid.