Answer
The IBF welterweight title was held by Kell Brook from 2014 to 2017. During his reign as champion, Brook successfully defended his title three times against mandatory challengers. He defeated Jo Jo Dan in 2014, Frankie Gavin in 2015, and Kevin Bizier in 2016. However, he lost the title to Errol Spence Jr. in 2017, ending his three-year reign as champion.