Queen consort of Spain in the context of Maria Christina of the Two Sicilies

Elisabeth Farnese (Italian: Elisabetta Farnese, Spanish: Isabel de Farnesio; 25 October 1692 – 11 July 1766) was Queen of Spain by marriage to King Philip V. She was the de facto ruler of Spain from 1714 until 1746, since she managed the affairs of state with the approval of her spouse. She is particularly known for her great influence over Spain's foreign policy. From 1759 to 1760, she governed as regent.

Elisabeth born in 1692 in Parma, the daughter of Odoardo Farnese, Hereditary Prince of Parma and his wife, Countess Palatine Dorothea Sophie of Neuburg. Elisabeth would be their only child to survive into adulthood, her only siblings dying infancy. Her father died in 1693, and her mother later remarried to his younger brother (Elisabeth's uncle), Francesco, in hopes for another heir. This never happened, and Elisabeth remained sole heiress. Elisabeth's marriage was considered of great political importance, and she received many proposals, notably from Piedmontese and Modenese princes, ultimately being married to the Spanish king, Philip V, whose first wife, Queen Maria Luisa, had died earlier that year.

Maria Christina of the Two Sicilies (Italian: Maria Cristina Ferdinanda di Borbone, Principessa delle Due Sicilie, Spanish: María Cristina de Borbón, Princesa de las Dos Sicilias; 27 April 1806 – 22 August 1878) was the Queen of Spain from 1829 to 1833 and Queen regent of the kingdom from 1833, when her daughter became queen at age two, to 1840. By virtue of her short marriage to King Ferdinand VII of Spain, she became a central character in Spanish history for nearly 50 years, thanks to introducing a bicameral model of government based on the Bourbon Restoration in France: the Spanish Royal Statute of 1834.

Maria Luisa of Parma (Luisa Maria Teresa Anna; 9 December 1751 – 2 January 1819) was, by marriage to King Charles IV of Spain, Queen of Spain from 1788 to 1808 leading up to the Peninsular War. Her relationship with Manuel Godoy and influence over the King made her unpopular among the people and aristocrats. She was rivals with the Duchess of Alba and the Duchess of Osuna. The death of her daughter-in-law Princess Maria Antonia of Naples and Sicily, whom she disliked, was said to be the result of poisoning by the Queen.