Problem: Background: Villa told a number of conflicting stories about his early life, and his "early life remains shrouded in mystery." According to most sources, he was born on 5 June 1878, and named Jose Doroteo Arango Arambula at birth. His father was a sharecropper named Agustin Arango, and his mother was Micaela Arambula. He grew up at the Rancho de la Coyotada, one of the largest haciendas in the state of Durango.
Context: After Villa successfully captured the strategic prize of Torreon, Carranza ordered Villa to break off action south of Torreon and instead to divert to attack Saltillo. He threatened to cut off Villa's coal supply, immobilizing his supply trains, if he did not comply. This was widely seen as an attempt by Carranza to divert Villa from a direct assault on Mexico City in order to allow Carranza's forces under Alvaro Obregon, driving in from the west via Guadalajara, to take the capital first. This was an expensive and disruptive diversion for the Division del Norte. Villa's enlisted men were not unpaid volunteers but paid soldiers, earning the then enormous sum of one peso per day. Each day of delay cost thousands of pesos.  Disgusted but having no practical alternative, Villa complied with Carranza's order and captured the less important city of Saltillo, and then offered his resignation. Felipe Angeles and the rest of Villa's staff officers argued for Villa to withdraw his resignation, defy Carranza's orders, and proceed to attack Zacatecas, a strategic railroad station heavily defended by Federal troops and considered nearly impregnable. Since the colonial era, Zacatecas was the source of much of Mexico's silver, and thus a supply of funds for whoever held it. Villa accepted his staff's advice and cancelled his resignation, and the Division del Norte defied Carranza and attacked Zacatecas. Attacking up steep slopes, the Division del Norte defeated the Federals in the Toma de Zacatecas (Taking of Zacatecas), the single bloodiest battle of the Revolution, with Federal casualties numbering approximately 7,000 dead and 5,000 wounded, and unknown numbers of civilian casualties. (A memorial to and museum of the Toma de Zacatecas is on the Cerro de la Bufa, a key defense point where the Federal Army was entrenched.)  Villa's victory at Zacatecas in June 1914 broke the back of the Huerta regime. Huerta left the country on 14 July 1914. The Federal Army collapsed, ceasing to exist as an institution. In August 1914, Carranza and his revolutionary army entered Mexico City ahead of Villa. Civil war between the winners was the next stage of the Revolution.
Question: How did it break their back?
Answer: The Federal Army collapsed, ceasing to exist as an institution. In August 1914,

Background: Queens of the Stone Age are an American rock band formed in 1996 in Palm Desert, California. The band's line-up includes founder Josh Homme (lead vocals, guitar, piano), alongside band members Troy Van Leeuwen (guitar, lap steel, keyboard, percussion, backing vocals), Michael Shuman (bass guitar, keyboard, backing vocals), Dean Fertita (keyboards, guitar, percussion, backing vocals), and Jon Theodore (drums, percussion). Formed after the dissolution of Homme's previous band, Kyuss, Queens of the Stone Age developed a style of riff-oriented, heavy rock music. Their sound has since evolved to incorporate a variety of different styles and influences, including working with ZZ Top member Billy Gibbons, Nirvana drummer and Foo Fighters frontman Dave Grohl, and Screaming Trees frontman Mark Lanegan who has been a steady contributor to the band.
Context: Foo Fighters frontman and former Nirvana drummer, Dave Grohl, joined in late 2001 to record drums for their third album. Songs for the Deaf was released in August 2002, again featuring Lanegan, along with former A Perfect Circle guitarist Troy Van Leeuwen to the touring line-up following the album's release. Also featured on Songs for the Deaf for the final track "Mosquito Song" were former A Perfect Circle bassist Paz Lenchantin on viola and piano, and Dean Ween on guitar.  This record was supposed to sound bizarre--like lightning in a bottle. We also were extremely fucked up. It even sounds that way to me, like a crazy person. The radio interludes are supposed to be like the drive from L.A. to Joshua Tree, a drive that makes you feel like you're letting go--more David Lynch with every mile.  Songs for the Deaf was a critical hit and was certified gold in 2003, with sales of over 900,000. The singles "No One Knows" and "Go with the Flow" became hits on radio and MTV, with the former just outside the Billboard Top 40. "No One Knows" and "Go with the Flow" were also featured on the first iterations of the popular video games Guitar Hero and Rock Band (respectively).  The Songs for the Deaf tour culminated in a string of headline dates in Australia in January 2004. Grohl returned to his other projects and was replaced on the European leg of the tour by former Danzig drummer Joey Castillo, who joined the band full-time. After the tour, Homme fired Oliveri, as he was convinced that Oliveri had been physically abusive to his girlfriend: "A couple years ago, I spoke to Nick about a rumor I heard. I said, 'If I ever find out that this is true, I can't know you, man.'" Homme considered breaking up the band after firing Oliveri, but found a new determination to continue. Oliveri countered in the press that the band had been "poisoned by hunger for power" and that without him, they were "Queens Lite." He later softened his opinion and said: "My relationship with Josh is good. The new Queens record kicks ass." The two reportedly are still friends and as of October 2006, Oliveri was interested in rejoining the band. Oliveri later contributed to a Queens of the Stone Age for the first time in nine years, contributing backing vocals to the band's sixth album, ...Like Clockwork.
Question: Why did Grohl leave?
Answer: