First founded in the late 1990's by Osiel Cárdenas Guillén, aka El Mata Amigos. Then-head of the Cártel del Golfo, Los Zetas was a terror that would go on to become one of the greatest horrors that Northeastern Mexico has ever known.
Los Zetas beginnings were by no means humble, as all it's original members were defectors from the Mexican military. More specifically, its special forces apparatus known as GAFE (Grupo Aeromóvil de Fuerzas Especiales.)
These defectors, whom numbered well over thirty with an ex-special forces Lieutenant at their head, one Arturo Guzmán Decena (Z-1) would go on to create an organization which became known for it's brutal efficiency, ruthless executions, sophisticated radio networks and paramilitary styled operations.
Members of Los Zetas in their early days brought skills never before seen to the table of Cártel warfare, as well as connections which stretched beyond the borders of Mexico and deep into South America. More specifically Guatemala, where Los Zetas soon began recruiting members of the countries own special forces, the Kaibiles.
With all the weapons in the world they could ever want, Los Zetas found it self responsible for conducting hits, collecting money and securing drug routes on behalf of the Gulf Cártel - and soon found themselves the majority holders of power. They were well armed and well trained, but while the organization had grown over the years it still lacked the numbers of the over-all CDG. Which at the time was far more unified under Osiel and the greater Cárdenas family than it is now.
It didn't matter to the leadership however, and in 2010 after a faction of the CDG murdered a Zeta sicario by the name of El Concord, the Z's went to war.
Battles were fierce and execution videos began to plague the internet in a series of tit for tat killings. Dismembered bodies found themselves strewn about Tamaulipas' and Nuevo León's streets and eventually, as their numbers began to dwindle, Los Zetas were forced to begin recruiting from less experienced, younger stockpiles of would-be criminals. The CDG found it self in a similar situation as well as it's older generations of leaders and criminals began to die off or were arrested.
Narcomanta's advertising their desire to recruit those of military and policing backgrounds were openly hung from bridges and highway overpasses. Subsequently, this mass drive for recruits caused their numbers to surge, consolidating their power in cities like Nuevo Laredo, Ciudad Victoria and Piedras Negras.
Forced recruitment was not unheard of either, and there are many stories regarding gunmen of Los Zetas flagging down busloads of migrants and forcing them into open fields to fight to the death. The reward of the victors? Money, watches, guns and stolen vehicles - as well as a lifelong internship in one of the world's most violent crime groups.
Since that time, Los Zetas has remained a powerhouse in the theatre of Mexican organized crime. However, they suffered a fracture in December 2016 after some of the organization's older members became disenchanted with the group. This being a result of it's leaders, Z-40 and Z-42 appointing their nephew to take the reigns in a bid to keep the leadership under the thumb of the Treviño clan.
The resulting schism brought to life two new players from the Zetas school of crime: The Cártel del Noreste and the Old School Zetas. The latter of which has reportedly re-aligned themselves with the Matamoros faction of the Gulf Cártel.
Below you will find an incomplete and ever growing list of factions belonging to Los Zetas. It is important to note that this list may contain factions which have since become defunct or otherwise obsolete.
Comando Zetas (Operating in Reynosa, Matamoros, Nuevo Laredo, Miguel Alemán, Gustavo Díaz Ordaz, and Ciudad Mier as recently as 2015.)
El Circulo (Operating in Jimenéz, Ciudad Victoria, Madero and Abasolo.)
El Extranjero(Operating in Jimenéz, Ciudad Victoria, Madero and Abasolo.)
Grupo Delta Zeta(Operating in Valle Hermoso.)
Grupo Operativo Zetas(Operating in El Mante, Soto La Marina and Ciudad Victoria.)
Néctar Lima(Named after the radio code for Nuevo Laredo and operating therein.)
Unidad Zetas(Operating in Nuevo Laredo.)
A list of notable groups to split from Los Zetas, including organizations which rebelled against the leadership of Z-40 after the death of Z-3.
Cártel del Noreste (Loyal to Z-40 and the greater Treviño family.)
Grupo Bravos (Armed wing of the VEZ, led by Comandante Bravo 01 'El Oaxaco.')
Los Hijos del Diablo (Defunct, once operated in San Luis Potosí, Huasteca & Zacatecas for Z-50.)
Los Legionarios (Defunct. Supposedly founded by Z-50 and Z-7 'El Mamito.')
Los Talibanes (Operators of Z-50 in Quintana Roo; loyal to CDG.)
Sangre Nueva Zetas (AKA Los Bukanas, operating between Puebla & Veracruz as train robbers.)
Sangre Zetas (Founded by Z-50 'El Taliban.')
Vieja Escuela Zetas (Currently contesting CDN; aligned with CDG.)