Template:On this day - April 15

Peter I of Castile

• 1246 – Death of Pedro González Telmo, Patron of sailors (b. 1190).
• 1354 – In Cuéllar (present-day Spain), Peter I of Castile, known as "the Cruel" by his detractors and as "the Just" by his supporters, marries Juana de Castro.
• 1408 – Yusuf III, sovereign of the Nasrid Kingdom of Granada (present-day Spain), signs a truce with the Christians.
• 1493 – In Seville, Christopher Columbus is received in triumph after arriving from the first crossing of the Atlantic Ocean.
• 1581 – In Portugal, Philip II becomes King of Portugal when the Cortes of Tomar recognize him as such.
• 1717 – In Spain, the Royal Academy of Gentlemen Midshipmen is created, forerunner of the Spanish Naval Military School.
• 1810 – Death of Joaquín Fernando Garay, Spanish biologist (b. 1733).
• 1814 – The Cortes of Cádiz approve the provisional regulations of the National Militia.
• 1817 – Near Tarija (Upper Peru, present-day Bolivia), the Battle of La Tablada is fought, during the war of independence of Bolivia.
• 1848 – The Spanish minister Bertrán de Lis introduces the decimal monetary system and withdraws the maravedí as currency, replacing it with the tenth of a real.
• 1856 – In Panama, the Watermelon Slice Incident occurs, which will lead to the first U.S. intervention.
• 1869 – Birth of Concha Espina, Spanish writer (d. 1955).
• 1931 – Alfonso XIII sets sail into exile from Cartagena bound for Marseille.
• 1938 – In the course of the Spanish Civil War, the Francoist troops commanded by Alonso Vega occupy Vinaroz, splitting Republican Spain in two and isolating Catalonia.
• 1938 – Death of César Vallejo, Peruvian writer and poet (b. 1892).
• 1939 – Birth of Jaime Paz Zamora, politician and President of Bolivia from 1989 to 1993, sole survivor of the air crash planned against him by the government.
• 1953 – In Buenos Aires (Argentina), opponents of the constitutional Government of Juan Domingo Perón set off several bombs in the middle of a huge Peronist demonstration (terrorist attack in the Plaza de Mayo), leaving 90 wounded and 5 dead.
• 1961 – U.S. President John F. Kennedy orders the bombing of several Cuban airfields to destroy its air force in preparation for the invasion of Playa Girón (two days later).
• 2012 – In the city of Cartagena de Indias (Colombia), the 6th Summit of the Americas ends without a final declaration being reached on the issue of the inclusion of Cuba, although it was supported by all the attending countries except the United States and Canada.