The longest-reigning undisputed male championship reign in the four-belt era has come to an end.

Saul 'Canelo' Alvarez was stripped of his IBF super middleweight title for failure to honor an overdue mandatory title defense. The four-division champion was previously summoned to face unbeaten IBF No. 1 contender William Scull.

A promise of a reached deal came without proper documentation and an effort to side step the fight. In lieu of his, Alvarez (61-2-2, 39 knockouts) chose to proceed with plans for a showdown with Edgar Berlanga (22-0, 17 KOs). Their RING/unified championship fight was announced on Thursday and will headline a Sept. 14 Pay-Per-View event from T-Mobile Arena in Las Vegas.

The declaration triggered the IBF to take action.

"Saul Alvarez’s mandatory defense of the IBF Super Middleweight title is overdue," the IBF confirmed via press statement. "Therefore, the bout scheduled for September 14, 2024, is not in compliance with the noted rule.

"The IBF places the upmost importance on keeping a title occupied. [F]urthermore values and understands the significance of the Undisputed Champion status for a fighter such as Saul Alvarez, the sport and the fans. We understand that Saul Alvarez and his team made a choice to pursue the route they see fit for his career in the bout against Edgar Berlanga.

"Nevertheless, the IBF rules are clear and were designed to serve all affected parties in a matter such as this. Based on the foregoing, the IBF was left with no other recourse than to vacate the IBF Super Middleweight."

Guadalajara's Alvarez, No. 4 pound-for-pound, still holdsThe Ring championshipand the WBA, WBC and WBO belts. All will be at stake on Sept. 14 for his seventh championship defense at the weight.

Alvarez has held the RING, WBA and WBC belts since a Dec. 2020 win over then-unbeaten Callum Smith in San Antonio, Texas. He then dethroned unbeaten WBO titlist Billy Joe Saunders at AT&T Stadium, home to the NFL's Dallas Cowboys.

The division was fully unified later that year. Alvarez stopped Caleb Plant in the eleventh round of their Nov. 2021 undisputed clash in Las Vegas. Plant previously made an IBF mandatory title defense in a Jan. 2021 points win over Caleb Truax.

Per the rotation system for unified and undisputed champions, the IBF was up this time around.

Alvarez's previously satisfied mandatory was last May, when he defeated interim WBO titlist John Ryder in Zapopan, Mexico. He went on to face Jermell Charlo, the undisputed 154-pound champ who moved up two divisions last Sept. 30. Alvarez won via unanimous decision, as well as in his May 4 optional defense versus Tijuana's Jaime Munguia (43-1, 34 KOs),No. 4 at 168 by The Ring.

The mandatory versus Scull was ordered nine days later, on May 13. The chain of events which followed ultimately violated sanctioning body by-laws.

"On May 22, 2024, the IBF received an email from Hagen Doering, on behalf of William Scull, requesting an immediate purse bid," the IBF explained. "The IBF sent notification on May 27, 2024, that a purse bid would be held on June 6, 2024. Subsequently, on June 4, 2024, the IBF received an email from Hagen Doering [of AGON Sports] requesting a postponement of the June 6, 2024, purse bid. Shortly thereafter Eddie Reynoso, on behalf of Saul Alvarez, agreed in writing to postpone the said purse bid.

"On June 18, 2024, the IBF received emails from both parties indicating that an agreement had been reached. Accordingly, the IBF sent notification that the purse bid rescheduled for June 18, 2024, had been cancelled.  However, the terms of the “agreement” were not disclosed to the IBF.  Tom Brown, on behalf of Saul Alvarez, sent a letter to the IBF on July 5, 2024, requesting an exception to participate in an optional defense of the Super Middleweight title on September 14, 2024, against a fighter to be determined.

"On July 19, 2024, the IBF Board of Directors met via video conference to discuss this matter. A majority of the directors determined that the request should not be considered pursuant to Rule 11.A [which] states in part:

"On July 25, 2024, the IBF was advised that Saul Alvarez was going to participate in an optional bout against #4 ranked Super Middleweight contender Edgar Berlanga on September 14, 2024. IBF Rule 5.B.2. states in part:

While not included in its announcement, the IBF is expected to order a vacant title fight between Scull (22-0, 9 KOs) andRing No. 7-ratedVladimir Shishkin (16-0, 10 KOs).

Meanwhile, the rest of Alvarez's reign figures to proceed uninterrupted.

Berlanga,No. 9 at 168 by The Ring, is the WBA mandatory challenger.

David Benavidez (29-0, 24 KOs), The Ring's No. 1 super middleweight, vacated his interim WBC belt at the weight to campaign at 175. The unbeaten former two-time full WBC titlist holds an interim belt at light heavyweight.

Diego Pacheco (21-0, 17 KOs), No. 6 at 168, is the WBO's top-rated contender, but not yet named as mandatory. Even if he were, the unbeaten South Central native is already scheduled to fight Aug. 31 in Carson, California.

Alvarez made four successful defenses as the undisputed championship, the most by any male boxer since the WBO gained worldwide acclaim as 'the fourth sanctioning body.'