UFC 40: Vendetta was a mixed martial arts event held by the Ultimate Fighting Championship on November 22, 2002, at the MGM Grand Arena on the Las Vegas Strip in Paradise, Nevada. The event was broadcast live on pay per view in the United States, and later released on DVD.

UFC 40 contained one of the biggest, most important and most anticipated fights in UFC history, a UFC Light Heavyweight Championship fight between rivals Tito Ortiz and Ken Shamrock. Shamrock, a popular legendary fighter and former champion from the UFC's early years, was returning to the UFC for the first time since 1996. The fight was coined "the biggest fight in UFC history" by the UFC during the event.

UFC 40 also contained a Welterweight Title Bout between Matt Hughes and Gil Castillo. Tank Abbott provided an interview in the octagon after UFC president Dana White had announced Abbott would return to the octagon on a 3-fight deal.

Bruce Buffer has said many times that the fight between Ken Shamrock and Tito Ortiz was one of the greatest fights he has ever seen, and that the energy from the 13,700 fans that night was one of the greatest feelings he has ever experienced.

Erick Silva (born June 21, 1984) is a Brazilian professional mixed martial artist who competes in the welterweight division. A professional MMA competitor since 2005, Silva has spent the majority of his career in Brazil, mostly notably for Jungle Fight where he was the inaugural Welterweight champion.

Silva comes from Vila Velha, Brazil and was an X-Gym training partner for the likes of Anderson Silva, Rafael Feijao and Jacare Souza. He also trains with Team Nogueira and Pro Fight.

Silva joined Jungle Fight, appearing at Jungle Fight 9 against Carlos Eduardo dos Santos. In the third and final round, Silva defeated dos Santos via rear naked choke.

At Jungle Fight 11, he defeated Igor Fernandes via unanimous decision. Silva followed that up with two further victories in the promotion.

Silva then competed in one of the more unique fights in his career, at Jungle Fight 17, which was held outdoors. On the day of the event, the weather was clear throughout, until less than an hour before the start, when rain began to fall and never stopped. The event, which went down as one of the wettest in MMA history was not a successful one for Silva who hit his downed opponent with a knee, resulting in a no contest verdict.

Kenneth Wayne Shamrock (born Kenneth Wayne Kilpatrick; February 11, 1964) is an American mixed martial artist, UFC Hall of Famer and professional wrestler. Shamrock emerged as one of the biggest stars in the history of mixed martial arts, headlining over 15 main events and co-main events in the Ultimate Fighting Championship and Pride Fighting Championships during the course of his career and set numerous pay per view records with his drawing power. Shamrock is widely considered to be a legendary figure and icon in the sport of mixed martial arts. Shamrock was named The World's Most Dangerous Man by ABC News in a special entitled "The World's Most Dangerous Things" in the early part of his UFC career, a moniker which has become synonymous as his nickname.

Shamrock became known early on in the UFC for his rivalry with Royce Gracie. After fighting to a draw with Gracie in the inaugural Superfight, he became the first UFC Superfight Champion after defeating Dan Severn at UFC 6; the title was eventually renamed the UFC Heavyweight Championship when weight categories were introduced to the UFC. He was also the first foreign MMA Champion in Japan, winning the title of King of Pancrase. During his reign as the UFC Superfight Champion, he was widely considered the #1 mixed martial artist in the world. Shamrock was also ranked by Inside MMA as one of the top 10 greatest mixed martial arts fighters of all time.

Jacob Christopher "Tito" Ortiz (English: /tɪtɵ ɔərtɪs/) (born January 23, 1975) is an American mixed martial artist and former UFC Light Heavyweight Champion, having held the title from April 14, 2000 to September 26, 2003. Along with fighters like Randy Couture and Chuck Liddell, he was one of the sport's early stars. Ortiz ultimately became the biggest pay-per-view draw of 2006 for his fights with Liddell, Forrest Griffin, and Ken Shamrock.

Outside of his fighting career, Ortiz is the CEO of the Punishment Athletics MMA equipment and clothing line. He also owns an MMA training gym called Punishment Training Center, which is located in Huntington Beach, CA.

Jacob Christopher Ortiz was born to Samuel and Joyce Ortiz. He received his nickname "Tito," which means tyrant, from his father when he was a year old. He is the fourth child of his mother, Joyce, who had three sons from a previous marriage. His mixed heritage (Mexican father, American mother) has been reflected in his ring entrances as he has borne both Mexican and American flags.