Albert del Rosario, the former Philippine foreign affairs secretary who played a key role in leading the country’s victorious arbitration case against China over the South China Sea in 2016, passed away on Tuesday, his family announced.

Del Rosario received his Bachelor of Arts degree in Economics from Xavier University-Ateneo de Cagayan in 1961 and his Master of Business Administration from Harvard Business School in 1963.

Throughout his career, del Rosario held various high-ranking positions in both the public and private sectors.

He served as the Philippine Ambassador to the United States from 2001 to 2006 and again from 2011 to 2016. He was appointed Foreign Affairs Secretary by former President Benigno Aquino III in 2011, and he served in that role until 2016.

During his tenure, he oversaw the Philippines’ decision to take its dispute with China over the contested West Philippine Sea to an international court for the first time, which resulted in the 2016 arbitral ruling in favor of the Philippines, which rejected China’s expansive claims in the South China Sea.

He resigned from the Aquino government in 2016 due to health concerns.

President Ferdinand “Bongbong” Marcos Jr. extended his condolences to the late ambassador on Tuesday, saying the latter was “known for his patriotism and integrity.”

“I join the entire nation in mourning the passing of former Foreign Affairs Secretary Albert del Rosario, an honorable diplomat and an esteemed public servant,” the president said in a statement released by Malacañang.

Before he passed away, Del Rosario had been urging Marcos Jr. to uphold the Philippines’ 2016 arbitral triumph, which was in contrast to the stance of former president Rodrigo Duterte.

“I extend my deepest sympathies to the family and loved ones of Secretary del Rosario, who was known for his patriotism and integrity,” Marcos Jr. said. John Ezekiel J. Hirro