The former leader of the Gulf Cartel, Osiel Cárdenas Guillén, was captured in the city of Matamoros, Tamaulipas, on 14 March 2003  in a shootout between the Mexican military and Gulf Cartel gunmen.
He was one of the FBI Ten Most Wanted Fugitives, which was offering $2 million for his capture.
According to government archives, this six-month military operation was planned and carried out in secret; the only people informed were the President Vicente Fox, the Secretary of Defense in Mexico, Ricardo Clemente Vega García, and Mexico's Attorney General, Rafael Macedo de la Concha.
After his capture, Cárdenas was sent to the federal, high-security prison La Palma.
However, it was believed that Cárdenas still controlled the Gulf Cartel from prison, and was later extradicted to the United States, where he was sentenced to 25 years in a prison in Houston, Texas for money laundering, drug trafficking and death threats to U.S. federal agents.
Reports from the PGR and El Universal state that while in prison, Cárdenas and Benjamín Arellano Félix, from the Tijuana Cartel, formed an alliance.
Moreover, through handwritten notes, Cárdenas gave orders on the movement of drugs along Mexico and to the United States, approved executions, and signed forms to allow the purchase of police forces.
And while his brother Antonio led the Gulf Cartel, Cárdenas still made vital orders from La Palma through messages from his lawyers and guards.

The arrest and extradition of Cárdenas, however, caused for several top lieutenants from both the Gulf Cartel and Los Zetas to fight over important drug corridors to the United States, especially the cities of Matamoros, Nuevo Laredo, Reynosa, and Tampico—all situated in the state of Tamaulipas.
They also fought for coastal cities Acapulco, Guerrero and Cancún, Quintana Roo; the state capital of Monterrey, Nuevo León, and the states of Veracruz and San Luis Potosí.
Through his violence and intimidation, Heriberto Lazcano took control of both Los Zetas and the Gulf Cartel after Cardenas' extradition.
Lieutenants that were once loyal to Cárdenas began following the commands of Lazcano, who tried to reorganize the cartel by appointing several lieutenants to control specific territories.
Morales Treviño was appointed to look over Nuevo León; Jorge Eduardo Costilla Sánchez in Matamoros; Héctor Manuel Sauceda Gamboa, nicknamed El Karis, took control of Nuevo Laredo; Gregorio Sauceda Gamboa, known as El Goyo, along with his brother Arturo, took control of the Reynosa plaza; Arturo Basurto Peña, alias El Grande, and Iván Velázquez-Caballero alias El Talibán took control of Quintana Roo and Guerrero; Alberto Sánchez Hinojosa, alias Comandante Castillo, took over Tabasco.
However, continual disagreement was leading the Gulf Cartel and Los Zetas into an inevitable rupture.

On 18 August 2013, Gulf Cartel leader Mario Ramirez Trevino was captured.

United States vs Osiel Cárdenas Guillén
In 2007, Cárdenas was extradited to the United States and charged with the involvement of conspiracies to traffic large amounts of marijuana and cocaine, violating the "continuing-criminal-enterprise statute" (also known as the "drug kingpin statute"), and for threatening two U.S. federal officers.
The standoff the two agents had with the drug lord in 1999 in the city of Matamoros, Tamaulipas led for the U.S. to indict Cárdenas and pressure the Mexican government to capture him.
In 2010 he was finally sentenced to 25 years in prison after being charged with 22 federal charges; the courtroom was locked and the public prevented from witnessing the proceeding.
The proceedings took place in the United States District Court for the Southern District of Texas in the border city of Brownsville, Texas.
Cárdenas has been isolated from interacting with other prisoners in the supermax prison he is in.

Nearly $30 million of the former drug lord's assets were distributed among several Texan law enforcement agencies.
In exchange for another life-sentence, Cárdenas agreed to collaborate with U.S. agents in intelligence information.
The U.S. federal court
The former leader of the Gulf Cartel, Osiel Cárdenas Guillén, was captured in the city of Matamoros, Tamaulipas, on 14 March 2003  in a shootout between the Mexican military and Gulf Cartel gunmen. He was one of the FBI Ten Most Wanted Fugitives, which was offering $2 million for his capture. According to government archives, this six-month military operation was planned and carried out in secret; the only people informed were the President Vicente Fox, the Secretary of Defense in Mexico, Ricardo Clemente Vega García, and Mexico's Attorney General, Rafael Macedo de la Concha. After his capture, Cárdenas was sent to the federal, high-security prison La Palma. However, it was believed that Cárdenas still controlled the Gulf Cartel from prison, and was later extradicted to the United States, where he was sentenced to 25 years in a prison in Houston, Texas for money laundering, drug trafficking and death threats to U.S. federal agents. Reports from the PGR and El Universal state that while in prison, Cárdenas and Benjamín Arellano Félix, from the Tijuana Cartel, formed an alliance. Moreover, through handwritten notes, Cárdenas gave orders on the movement of drugs along Mexico and to the United States, approved executions, and signed forms to allow the purchase of police forces. And while his brother Antonio led the Gulf Cartel, Cárdenas still made vital orders from La Palma through messages from his lawyers and guards.
The arrest and extradition of Cárdenas, however, caused for several top lieutenants from both the Gulf Cartel and Los Zetas to fight over important drug corridors to the United States, especially the cities of Matamoros, Nuevo Laredo, Reynosa, and Tampico—all situated in the state of Tamaulipas. They also fought for coastal cities Acapulco, Guerrero and Cancún, Quintana Roo; the state capital of Monterrey, Nuevo León, and the states of Veracruz and San Luis Potosí. Through his violence and intimidation, Heriberto Lazcano took control of both Los Zetas and the Gulf Cartel after Cardenas' extradition. Lieutenants that were once loyal to Cárdenas began following the commands of Lazcano, who tried to reorganize the cartel by appointing several lieutenants to control specific territories. Morales Treviño was appointed to look over Nuevo León; Jorge Eduardo Costilla Sánchez in Matamoros; Héctor Manuel Sauceda Gamboa, nicknamed El Karis, took control of Nuevo Laredo; Gregorio Sauceda Gamboa, known as El Goyo, along with his brother Arturo, took control of the Reynosa plaza; Arturo Basurto Peña, alias El Grande, and Iván Velázquez-Caballero alias El Talibán took control of Quintana Roo and Guerrero; Alberto Sánchez Hinojosa, alias Comandante Castillo, took over Tabasco. However, continual disagreement was leading the Gulf Cartel and Los Zetas into an inevitable rupture.
On 18 August 2013, Gulf Cartel leader Mario Ramirez Trevino was captured.
United States vs Osiel Cárdenas Guillén
In 2007, Cárdenas was extradited to the United States and charged with the involvement of conspiracies to traffic large amounts of marijuana and cocaine, violating the "continuing-criminal-enterprise statute" (also known as the "drug kingpin statute"), and for threatening two U.S. federal officers. The standoff the two agents had with the drug lord in 1999 in the city of Matamoros, Tamaulipas led for the U.S. to indict Cárdenas and pressure the Mexican government to capture him. In 2010 he was finally sentenced to 25 years in prison after being charged with 22 federal charges; the courtroom was locked and the public prevented from witnessing the proceeding. The proceedings took place in the United States District Court for the Southern District of Texas in the border city of Brownsville, Texas. Cárdenas has been isolated from interacting with other prisoners in the supermax prison he is in.
Nearly $30 million of the former drug lord's assets were distributed among several Texan law enforcement agencies. In exchange for another life-sentence, Cárdenas agreed to collaborate with U.S. agents in intelligence information. The U.S. federal court 
Gulf Cartel