- Gaudencio Rosales was born Gaudencio Borbon Rosales on 10 August 1932 in Batangas City, Batangas, Philippines.
- Gaudencio Rosales studied theology at the San José Seminary and had as classmates two other future bishops Bishop Severino Pelayo, former bishop of the Military Ordinariate, and Bishop Benjamin Almoneda, former Bishop of Daet.
- Gaudencio Rosales was ordained on 23 March 1958 by Bishop Alejandro Olalia and was assigned to teach for 11 years in the seminary of the Diocese of Lipa.
- Gaudencio Rosales was given his first parish assignment in 1970 at the obscure barrio of Banay-banay and was later transferred to the biggest parish of the diocese in Batangas City.
- Gaudencio Rosales the first Batangueño to become auxiliary bishop of Manila and was appointed by Pope Paul VI on 12 August 1974.
- Gaudencio Rosales was consecrated bishop of the titular see of Oescus in a ceremony on 28 October 1974 and was appointed rector of the archdiocesan major seminary, San Carlos Seminary in 1980.
- Gaudencio Rosales was appointed coadjutor bishop on 9 June 1982 to the controversial and prophetic Bishop Francisco Claver of the Diocese of Malaybalay, Bukidnon and on 14 September 1984 he succeeded the Bishop of Malaybalay.
- Gaudenctio Rosales was appointed by Pope John Paul II on 15 September 2003 and was enthroned in Manila Cathedral on 21 November 2003 becoming the 31st Archbishop of Manila and the fourth native Filipino to hold the post following centuries of Spanish, American, and Irish prelates and succeeded Jaime Cardinal Sin after his retirement.
- During his last year as archbishop, he was concurrently named Apostolic Administrator of the Diocese of Pasig from December 21, 2010 to April 20, 2011, a post he accepted after the resignation of Pasig's first bishop, Francisco San Diego.
- Gaudencio Rosales was created Priest of Santissimo Nome di Maria in Via Latina in the consistory of 24 March 2006 by Pope Benedict XVI joining fourteen others, two of them Asians, as the newest members of the College of Cardinals.
- On 13 October 2011, two months after his 79th birthday, Pope Benedict XVI finally accepted his resignation and appointed the then Bishop of Imus, Luis Antonio Tagle, as his successor.
- The 2013 Global Peace Award for Service was awarded to Cardinal Gaudencio Borbon Rosa.