Called the Día de la Raza, or 'Day of Race', in Mexico, the holiday is commemorated by millions across Latin America and Spain.
Cristóbal Colón, better known in English as Christopher Columbus, landed on the island of Guanahani on October 12, 1492 - the date that is now remembered.
Colón, born in Genoa, Italy, was on a voyage of discovery across the Atlantic for the Spanish crown when his ship first sighted Guanahani. There is still debate over where the island was, but it is widely believed to be modern day San Salvador in the Bahamas, not far from Florida.
The pan-American holiday was first named by ex-minister of Spain, Faustino Rodríguez-San Pedro, as President of the Ibero-American Union in 1913. He wanted to establish an event to help unite Spain and Latin America and celebrate the diversity of the peoples of the American continent, many of which now shared a mixture of European and indigenous blood.
Political controversy and regional historic differences meant that the day was officially recognized or adapted in different countries with different titles in the decades that followed.
In Mexico, the day was first officially commemorated in 1928, under the initiative of José Vasconcelos Calderón, a well-known Mexican writer and philosopher.
In the United States, 'Columbus Day' is a related holiday, also held on October 12. It is commemorated mainly by Italian-Americans in celebration of their heritage.
