The Gulf Cártel was first founded in the 1980's and is remarked as one of the oldest crime groups in Mexico.
This volatile and violent grouping of crime families has entrenched it self almost indisputably over the past several decades as a ruler of Tamaulipas, it's primary area of operations.
They were responsible for the founding of Los Zetas, whom would later breakaway, and have been responsible for untold amounts of grief in cities like Reynosa, Matamoros, Rio Bravo, Tampico, Ciudad Madero, Altamira and others.
In more recent times, while their grip upon the state remains they have been subject to several violent fractures which have resulted in a staggering amount of sub-factions beneath the CDG banner. To which point it is difficult to say the organization has any form of core leadership or ruling counsel as we see in the Cártel de Sinaloa, and to some extent in the Cártel del Noreste.
The CDG seems to make the majority of its revenue through extortion, drug trafficking, abduction for purposes of ransom and arms trafficking. They regularly work alongside police, border services and anyone else foolish enough to fall into their web of deceit and coercion.
They are considered to be one of the most violent groups in Mexico and have a large variety of Narcocorridos and Narco Rap songs dedicated to their various members, as well as posting their sadistic exploits on Youtube and other media sites online.
While they lack an over-all leadership, they instead seem to be divided up into plaza based factions. For example, Los Metros is perhaps best known for its hold over Reynosa. While Los Ciclones and their allies fall under the umbrella term of the 'Matamoros CDG' for the city they call their stronghold. (This including Ciclones, Alfas, Alacranes, Grupo Escorpion, Los Ceros and even the Old School Zetas reportedly.)
Beyond this we have the Tampico network of Los Rojos, sometimes referred to as the CDG del Sur who seem to have a number of support groups under their employ. (Los Medusas, Grupo Black de Madero, Grupo Nietos and Rojos Zona Norte for example.)
There are dozens of other factions of the CDG currently operating countrywide, with others like CDG Zacatecas and CDG Centro being notables. There have also been reports of Metros operating in Sinaloa procuring drugs for re-sale back in Reynosa, though these have not been substantiated. (La Muñeca, 35-M85 for example.)
As a whole, while the Golfos may be fractured and fraught with infighting, they remain one of the most powerful groups in Mexico - and especially in Tamaulipas.
Below you will find an incomplete and ever growing list of factions belonging to the Cártel del Golfo. It is important to note that this list may contain factions which have since become defunct or otherwise obsolete.
Grupo Alfa (Support group aiding Los Ciclones in Matamoros.)
Los Alacranes (Operators in Ciudad Madero.)
Grupo Black de Madero (Seem to be linked to Grupo Rojos.)
Los Bravos (Operators of Kaliman 24 and Kaliman 17.)
Grupo Bravos (Armed wing of the Old School Zetas under Cmdte Bravo 01.)
Los Camellos de Tampico
Los Ceros (Operative group of Señor Cortez in Matamoros & Reynosa.)
Los Ciclones (Sometimes referred to as the Matamoros CDG. Loyal to Cárdenas family.)
Los Deltas (Reportedly taken over by Cmdte Diablo and rebranded as such.)
Los Dragones (Operators of El Sheyla, since ousted from Tampico by Los Rojos.)
Grupo Escorpion (Operators of the now deceased Tony Tormenta.)
Los Fresitas (Operatives of El Chive whom worked to oust Los Dragones from Tampico.)
Los Jaguares (Loyalists of X-20 in Rio Bravo.)
Los Jimmys (Operators of El Paisano in Altamira. Since defunct I believe.)
Los Kalimanes (Operators of Cmdte Sierra.)
Las Kumbias (Possibly operators of M-24 El Simple, aka Wero Cumbias?)
Grupo L (Operators of El Karis, brother of M-2.)
Los Lobos (Founded to work in Nuevo Laredo. Since split down between Zetas/CDG.)
Los Medusas (Reportedly a support group in Tampico of female sicarias.)
Grupo Metros (Sometimes referred to as the Reynosa CDG.)
Grupo Michelin (Now defunct operators of Gringo Mike de Los Metros.)
Operativa Nuevo León
Grupo Nietos (Appear to be a support group in Tampico.)
Grupo Omegas (Operators in Monterrey, Nuevo León?)
Los Panteras (Trusted operators of X-20.)
Los Pelones (Operators in the state of Quintana Roo.)
Grupo Rojos de Tampico (Organization of El Chive in Tampico.)
Grupo Rojos Zona Norte (Further operators of El Chive?)
Operativa Rusos 956 (Operatives of Cmdte Ruso of Los Talibanes? Deceased Jan 2018.)
Grupo Sierra (Immediate reaction force of Cmdte Sierra in Tampico.)
Grupo Sombra (Operators in Veracruz. Seem to have popped up 2016 - onwards.)
Grupo Talibanes (Operators of Z-50 El Taliban.)
Los Tangos (Originally founded to operate in Tampico? Since defunct I believe.)
Grupo Tiburones (Seem to still be active in Matamoros.)
Los Tigres (Operators of Kaliman 12 El Tigre.)
Vieja Escuela Zetas (Formed as part of the Dec 2016 Los Zetas fracture.)