The Gulf organization emerged in the northern state of Tamaulipas and has been the dominant OCG in the region until recently. Its roots are in prohibition-era bootlegging operations. During the 1980s the organization leader, Juan García Abrego, partnered with Colombia's Cali cartel to traffic cocaine into the United States via the Gulf of Mexico.
Following internal competition and reorganizations, Osiel Cárdenas Guillén, took over leadership of the Gulf organizations and developed a close relationship with former members of Mexican Special Forces known as the Grupo Aeromovil de Fuerzas Especiales (GAFES). Cárdenas Guillén helped to organize these ex-soldiers into his own enforcers force. Eventually, the Zetas became increasingly powerful and developed their own autonomy within the Gulf organization, breaking away in 2009.
Initially the Zetas were used as specially trained hit men, but they also helped ensure that the Gulf OCG retained control of territory along the U.S.-Mexico border including the key border-crossings in Nuevo Loredo and Reynosa. The Zetas helped to control areas of the country such as Matamoros and Nuevo Laredo on behalf of the Gulf organization, especially following the 2003 arrest of Osiel Cardenas and increasingly bold challenges by the Sinaloa OCG to wrest control away from the Gulf organization.
To strengthen its defenses against Sinaloa, the Gulf organization originally joined forces with the AFO, who was already caught up in a battle with the Sinaloa OCG over interior transshipment points in states such as Guerrero and Michoacán.
One of the major developments of 2010 was the breakdown in relations between the Gulf the Zetas. The break has resulted in a serious spike in violence in the Northeastern corridor of Mexico, and has led to changing alliances between the Gulf organization and a former rival, La Familia Michoacana, who broke with Los Zetas and the Gulf OCG in 2006, and the Sinaloa OCG. All three organizations now appear to be working together to eliminate Los Zetas.
The break between Los Zetas and Gulf organizations was allegedly precipitated by the killing of a Gulf leader by Zeta henchmen, and the refusal of Los Zetas to pay penances by turning over to the Gulf the person responsible for the murder. But these events where also preceded by the fact that Los Zetas had been developing their own power base by expanding their activities into trafficking and smuggling in persons, extortion, drug smuggling, and expanding their presence in Central America..
Antonio Ezequiel Cárdenas Guillén, also known as "Tony Tormenta", became the leader of the Gulf OCG along with Jorge Eduardo Costilla Sanchez, after the arrest of his brother Osiel Cárdenas Guillén in 2003. Tony Tormenta was listed as a Most-Wanted fugitive by both the United States and Mexico. The escalating violence between Mexican federal forces and the Gulf OCG peaked during a bloody shootout in Matamoros, Tamaulipas on November 5, 2010. The federal operation was the result of six months of intelligence work and involved more than 150 Mexicans Marines. Tony Tormenta, along with four other members of the cartel, two marines, and a journalist were killed during the operation.