 On August 11, 2011 the capture of one of the cartel's former top lieutenants, called "the last Beltran-Leyva link of any importance", prompted Mexican authorities to declare the cartel disbanded and extinct.Born in the Sinaloan countryside in the 1960s, the Beltrán Leyva brothers — Arturo, Carlos, Alfredo, Mario Alberto and Héctor — worked closely with Joaquín "El Chapo" Guzmán, the leader of the Sinaloa Cartel, during decades of smuggling.Sensing a void in the rival Gulf Cartel after Osiel Cárdenas' arrest on March 14, 2003, the Sinaloa Cartel began to move into Gulf Cartel territory.