Tracking the championship: UFC lightweight division

Jens Pulver

Successful title defenses: 2.
Jens Pulver became the inaugural 155-pound champion by beating Caol Uno at UFC 30 on Feb. 23, 2001. Six months later, he beat Dennis Hallman at UFC 33. On Jan. 11, 2002, at UFC 35, Pulver won a majority decision over B.J. Penn for his second successful title defense. Pulver left the UFC over a contract dispute shortly thereafter and was stripped of his title.

Sean Sherk

Successful title defenses: 1.
Sean "Muscles Shark" Sherk beat Kenny Florian for the lightweight title at UFC 64 on Oct. 14, 2006. Sherk became the first lightweight champion in the UFC since Jens Pulver vacated the belt in 2002. Sherk beat Hermes Franca at UFC 73 on July 7, 2007. After the fight, Sherk tested positive for anabolic steroids (as did Franca). He was suspended by the California State Athletic Commission, and in December 2007, the UFC stripped him of the title when his appeal did not overturn the result of the tests. (It reduced his suspension from one year to six months.)

B.J. Penn

Successful title defenses: 3.
B.J. Penn beat Joe Stevenson via second-round submission at UFC 80 on Jan. 19, 2008, to win the vacant UFC lightweight title. Sean Sherk had been stripped of the title after a steroid suspension. Later that May, Penn beat Sherk via third-round TKO. After an unsuccessful attempt to win the welterweight title against Georges St-Pierre in January 2009, Penn then returned to lightweight and defended his title twice more, submitting Kenny Florian at UFC 101 and stopping Diego Sanchez with a fifth-round TKO by doctor's stoppage at UFC 107 on Dec. 12, 2009. Penn lost the title to Frankie Edgar the following April at UFC 112.

Frankie Edgar

Successful title defenses: 3.
Frankie Edgar surprised many in the MMA world when he beat B.J. Penn via unanimous decision at UFC 112 on April 10, 2010, in Abu Dhabi. Edgar beat Penn in the immediate rematch, then fought Gray Maynard to a draw. In the rematch with Maynard at UFC 136 on Oct. 8, 2011, Edgar won by fourth-round TKO to make it three straight title fights without having to surrender the belt to an opponent. Edgar lost the title to Benson Henderson at UFC 144 on Feb. 25, 2012.

Benson Henderson

Successful title defenses: 3.
Benson Henderson took the lightweight title from Frankie Edgar at UFC 144 on Feb. 25, 2012, then beat him again in the rematch six months later at UFC 150. Henderson, the last lightweight champion to make more than one successful title defense, also beat Nate Diaz and Gilbert Melendez before losing the belt to Anthony Pettis on Aug. 31, 2013.

Anthony Pettis

Successful title defenses: 1.
Anthony Pettis took the title from Benson Henderson with an impressive first-round submission on Aug. 31, 2013, at UFC 164. In his first title defense more than a year later at UFC 181 on Dec. 6, 2014, Pettis submitted Gilbert Melendez in the second round. The following March, Pettis lost his title to Rafael Dos Anjos by unanimous decision.

Rafael Dos Anjos

Successful title defenses: 1.
Rafael Dos Anjos dominated Anthony Pettis to win the title from him at UFC 185 on March 14, 2015, then returned from a knee injury that Decemeber to defend the title with a first-round knockout of Donald Cerrone. Dos Anjos lost the title to Eddie Alvarez a little more than one year after winning it.

Eddie Alvarez

Successful title defenses: 0

Eddie Alvarez won the lightweight title on July 7, 2016, by knocking out Rafael Dos Anjos in the first round with a blistering series of strikes. It was just the fourth UFC fight for Alvarez, who signed with the promotion in 2014 after a long legal dispute with Bellator.

Conor McGregor

Aiming to replicate his success in Cage Warriors, Conor McGregor set out to become the UFC's first two-weight world champion after winning he featherweight belt in 2015. He was scheduled to fight then-champion Rafael dos Anjos in March 2016, but was sidetracked by a new rivalry with Nate Diaz after dos Anjos pulled from their bout. McGregor finally got the chance to make history when he faced Eddie Alvarez at UFC 205, dominating the fight and finishing Alvarez in the second round to take home his second UFC belt.