It is named after Sergeant Major Melchor de Mencos y Varón, who in 1754 journeyed with a tiny contingent of Spanish colonial troops from what is now Antigua, Guatemala to the coast of present-day Belize, there to combat English "pirates" who had settled that region and established a self-governing community.

Large numbers of its young people attend secondary school across the border in Belize, seeking the competitive benefits of English-language fluency.

They can be seen when dropped off on weekday mornings at the Guatemalan end of the pedestrian border crossing, walking through, and boarding the same school buses at the Belizean end, from there to be transported onward to their secondary schools in Benque Viejo del Carmen, Melchor's twin city across the border in Belize, or further afield.

[2] Tensions along the border heightened in the autumn of 2014, following the shooting (presumably by a Guatemalan engaged in illegal exploitation of Belizean timber or other resources) at a major archaeological site in the Cayo District.

[citation needed] Prior to their relocation in 1989, Melchor de Mencos was home to the two training centres of the Guatemalan Army's elite Kaibiles special operations force.