Isabella II (Spanish: Isabel II; 10 October 1830 9 April 1904), was Queen of Spain from 29 September 1833 until 30 September 1868.

Shortly before her birth, the King Ferdinand VII of Spain issued a Pragmatic Sanction to ensure the succession of his firstborn daughter, due to his lack of a son. She came to the throne a month before her third birthday, but her succession was disputed by her uncle the Infante Carlos (founder of the Carlist movement), whose refusal to recognize a female sovereign led to the Carlist Wars. Under the regency of her mother, Spain transitioned from an absolute monarchy to a constitutional monarchy adopting the Royal Statute of 1834 and Constitution of 1837. Her effective reign was a period marked by palace intrigues, back-stairs and antechamber influences, barracks conspiracies, and military pronunciamientos. She was deposed in the Glorious Revolution of 1868, and formally abdicated in 1870. Her son, Alfonso XII, became king in 1874.

Isabela, officially the Province of Isabela (Ilocano: Probinsia ti Isabela; Ibanag: Provinsia na Isabela; Tagalog: Lalawigan ng Isabela) is the second largest province in the Philippines in land area located in the Cagayan Valley region in Luzon. Its capital and largest local government unit is the city of Ilagan. It is bordered by the provinces of Cagayan to the north, Kalinga to the northwest, Mountain Province to the central-west, Ifugao and Nueva Vizcaya to the southwest, Quirino and Aurora to the south, and the Philippine Sea to the east.

This primarily agricultural province is the rice and corn granary of Luzon due to its plain and rolling terrain. In 2012, the province was declared as the country's top producer of corn with 1,209,524 metric tons. Isabela was also declared the second-largest rice producer in the Philippines and the Queen Province of the North.Isabela is the 10th richest province in the Philippines as of 2011. The province has four trade centers in the cities of Ilagan, Cauayan, Santiago and the municipality of Roxas. Santiago City, one of Isabela's cities, is considered to have the fastest-growing local economy in the entire Philippines.