[4][5] According to "El Blasonario de la Consanguinidad Ibérica" (The Armorial of the Iberian Consanguinity) by genealogists Ampelio Alonso de Cadenas and Don Vicente de Cadenas y Vicent, Mejia is described as having been brought to Galicia and León by Sevillians who escaped to the mountainous northern provinces amidst the Moorish invasions of southern Spain, Prior to this, the bearers of the name had lived in Seville since Visigoth and Roman times.
[6] Another common theory is that the name may have Sephardic origins, from when the Spanish Kingdom forced Jewish settlers to change their surname to Castillian.
[7] However, others have argued that the name could have simply been assigned at baptism by a priest who chose to use a biblical word, rather than as a result of translation.
[8] In addition, Spaniards with any Jewish or Muslim ancestry were not allowed to emigrate to the New World colonies, and so this theory might not account for the extensive popularity of the surname in Latin America today.
As of 2014, 23.7% of all known bearers of the surname Mejía were residents of Mexico (frequency 1:450), 16.2% of Colombia (1:253), 14.4% of Honduras (1:53), 8.0% of Guatemala (1:172), 6.5% of the Dominican Republic (1:138), 6.3% of the United States (1:4,915), 6.3% of El Salvador (1:86), 4.7% of Peru (1:583), 2.9% of Ecuador (1:475), 2.8% of Nicaragua (1:185), 2.5% of the Philippines (1:3,461), 2.0% of Venezuela (1:1,266) and 1.8% of Bolivia (1:510).