From typicallyspanish.com

History
The House of Bourbon - Part Two - from the restoration of Bourbon rule to the First Spanish Republic
By h.b.
Jun 2, 2008 - 11:42 PM

Fernando VII: Born in El Escorial 1784, reigned 1808 (briefly), and 1813-1833. The eldest son of Carlos IV had initially come to the throne after an uprising which took place during Napoleon’s invasion of Spain had forced his father to abdicate. He spent almost seven years in prison in France, while Napoleon’s elder brother, Joseph, José I of Spain, held the Spanish crown, and war raged throughout the Iberian Peninsula in what is known as the Peninsular War, or the Spanish War of Independence.
Known as Fernando the Desired, he returned after Napoleon’s defeat, and overthrew the liberal historic 1812 Constitution passed by the Cortes national legislative body from refuge in Cádiz, restoring the premise of absolute power residing in the person of the monarch. He accepted the return of the Constitution after a military uprising led by Colonel Rafael Riego in 1820. The constitutional period only lasted three years until another invasion by France restored the King to absolute power. Fernando’s reign saw the loss of most of Spain’s colonies abroad, and sowed the seeds for the Carlist Wars when he abolished the law which established the order of succession in the male line, and passed over his brother, Carlos, for the throne in favour of his daughter, Isabela II. Fernando had married four times, but the only children who survived into adulthood were two daughters with his fourth wife, his niece, María Cristina de las Dos Sicilias.

Isabela II: Born in Madrid in 1830, reigned 1833-1868. Isabela was less than three years old when she inherited the throne from her father, and the crown was held in regency first by her mother, María Cristina de las Dos Sicilias, and then by General Baldomero Espartero, until she reached the age of 13 in 1843. The period of regency was marked by seven years of war as her uncle, the Infante Carlos María Isidro de Borbón, and his supporters fought for his right to the crown. She married her cousin, Francisco de Asís de Borbón, the Duke of Cádiz, at the age of 16, and had 12 children, only four of which survived into adulthood. Isabela’s reign was a turbulent period in Spain, with more than 60 changes of government, the Queen’s alliances with the military and scandalous private life, which finally saw her forced off the throne by a revolution in 1868 into exile in Paris, and the end of the second period of Bourbon rule in Spain.
A regency was created and the 1869 Constitution was passed by the Cortes in June 1869. The Cortes decided to offer the throne to Amedeo of Savoy, the younger son of Victor Emmanuel II of Italy, passing over Isabela’s son, Alfonso, who his mother had abdicated in favour of in Paris in June 1870. Amedeo, Duke of Aosta, became Amadeo I of Spain on 2nd January 1871.
Amadeo was only on the throne until 11 February 1873, when he abdicated and the First Spanish Republic was proclaimed.