WASHINGTON — Bishop Kevin Vann of Fort Worth, Texas, has been named the fourth bishop of Orange, Calif., by Pope Benedict XVI.

Bishop Vann will succeed Bishop Tod Brown, who offered his resignation to Pope Benedict earlier this year upon reaching the age limit of 75.

The appointment and resignation were both announced Sept. 21 in Washington by Archbishop Carlo Viganò, apostolic nuncio to the United States.

Bishop Vann will shepherd the nation’s 10th largest and fastest-growing diocese.

The diocese’s total population is 3.2 million, 41% of whom are Catholic.

Bishop Brown recently purchased the famous Crystal Cathedral from an evangelical church, and it will become the cathedral and chancery of Orange known as Christ Cathedral.

Bishop Vann was introduced to the diocese at 11:30am local time at the Marywood Pastoral Center. He will be assisted in his governance of the diocese by auxiliary Bishop Dominic Luong, who has served Orange since 2003.

Bishop Vann was born in Springfield, Ill., in 1951 and was ordained a priest for the Diocese of Springfield in 1981.

He earned a doctorate in canon law from the Pontifical University of St. Thomas Aquinas in Rome (Angelicum) in 1985, and he subsequently served as both a pastor and on the tribunal of the diocese. He was named coadjutor bishop of Fort Worth in 2005, assuming the helm later that year.

Bishop Brown was ordained a priest of the Diocese of Monterey-Fresno, Calif., in 1963 and has been bishop of Orange for 14 years.

Archbishop Viganò also made public that Pope Benedict accepted the resignation of Bishop Matthew Clark of the Diocese of Rochester, N.Y., who also turned 75 this year.

Rochester will be led by an apostolic administrator, Bishop Robert Cunnningham of Syracuse, N.Y., until the Pope appoints a successor.