Template:On this day - August 15

Alfonso VI of León and Castile

• 1097 – The Battle of Consuegra (Toledo) takes place between the troops of Alfonso VI of León and Castile and those of the Almoravid emir Yusuf ibn Tashfin.
• 1284 – Joan I of Navarre marries Philip IV of France, through which she would become Queen of France a year later.
• 1351 – Alfonso XI conquers the town of Alcalá la Real (present-day Spain) from the Muslims.
• 1466 – Henry IV of Castile grants the mayors of Guipúzcoa powers to pass sentence in cases of witchcraft.
• 1496 – In the south of the Island of Hispaniola (present-day Dominican Republic and Haiti) the city of Santo Domingo is founded.
• 1511 – On the Island of Cuba, the adelantado Diego Velázquez de Cuéllar founds the settlement of Nuestra Señora de la Asunción de Baracoa, one of the first towns founded by Spaniards in America, described by Christopher Columbus as "the most beautiful thing in the world".
• 1514 – On the Island of Hispaniola, Bartolomé de las Casas gives up the encomienda that had been assigned to him.
• 1519 – Pedrarias Dávila founds the city of Nuestra Señora de la Asunción de Panamá.
• 1534 – In the Governorate of New Castile, Sebastián de Belalcázar and Diego de Almagro found the city of Santiago de Quito (today Santiago de Guayaquil).
• 1537 – In the Governorate of the Río de la Plata, Juan de Salazar founds Asunción (today the capital of Paraguay).
• 1539 – In the Governorate of New Castile the Very Noble and Loyal City of the Knights of León de Huánuco (today Huánuco) is founded.
• 1540 – In the Governorate of New Castile, Garci Manuel de Carbajal founds the Villa de la Asunción de Nuestra Señora del Valle Hermoso de Arequipa (today Arequipa, in southern Peru).
• 1684 – In Regensburg (present-day Germany), the Spain of Charles II and the Holy Roman Empire of Leopold I of Habsburg sign a twenty-year truce with the France of Louis XIV, ending the so-called War of the Reunions.
• 1702 – An Anglo-Dutch squadron sacks the Spanish ports of Rota and El Puerto de Santa María.
• 1761 – At Versailles (France), the Spanish ambassador Jerónimo Grimaldi signs the Third Family Compact between Spain and France.
• 1812 – In the Plaza Mayor of Madrid (Spain) the Constitution of 1812, promulgated by the Cortes of Cádiz, is proclaimed.
• 1914 – The Panama Canal opens to maritime traffic, linking the Atlantic Ocean and the Pacific, with the passage of the American passenger and cargo steamship Ancon.
• 1938 – The first International Congress on the Teaching of Ibero-American Literature is held in Mexico.
• 1943 – The village of Asquerosa (Spain) changes its name to Valderrubio, to avoid the demonym "asquerosos" (disgusting ones).
• 1954 – In Paraguay, Alfredo Stroessner takes office as President of Paraguay, an office he will hold until February 3, 1989.
• 1968 – In Montevideo (Uruguay), a quarter of a million people take to the streets over the murder of the student Líber Arce (who died the previous day), against the government of Jorge Pacheco Areco.
• 1985 – In Barcelona the Banco Hispanoamericano is robbed, with a haul of more than 1,000 million pesetas (some 6 million euros).
• 1986 – The IMF (International Monetary Fund) suspends its credits to Peru.
• 1991 – The Decolonization Committee of the UN reaffirms the right of Puerto Rico to self-determination and independence.
• 2004 – In Venezuela, Hugo Chávez wins the presidential referendum against him with 58% of the vote.
• 2008 – In Paraguay, former bishop Fernando Lugo assumes the presidency, leaving behind more than 60 years of government by the Colorado Party (which included the dictatorship of Alfredo Stroessner between 1954 and 1989).