Rudy Boesch, a fan-favorite competitor of season one of Survivor and the franchise’s oldest contestant, has died at the age of 91.

The UDT/SEAL Association announced the death of the reality star and U.S. Navy vet on Saturday.

“It is with a broken heart that we inform you that Master Chief Rudy Boesch passed away last night,” the group said on Instagram. “Master Chief was a legend in the SEAL and Special Operations community. Rudy proudly served our Nation from 1944-1990 and his impact on so many individuals continues today. Please join us in respecting his family’s wishes of privacy until we can release more details. God Speed Rudy!”

Boesch had battled Alzheimer’s disease for years prior to his death, People reported. His death was preceded by the passing of his wife Marjorie Thomas in 2008. The two were married for 53 years and shared three children. 

Boesch had finished in third on the inaugural season of Survivor: Borneo in 2000 when he was 72 years old.

“I was the most popular,” he said in an interview posted on the Marine Corps website in 2004.

Richard Hatch, the first Survivor winner, paid tribute to him on Twitter.

“Ours was an interesting bond, Dear Rudy!” he wrote. “You and I helped open minds and undermine predjudces. While your time here has passed, you will remain loved and iconic, dear friend!”

Boesch, one of the most beloved Survivor contestants, also competed with other show alumni on season eight, Survivor: All Stars. He was the second contestant voted out.

Boesch jointed the Navy as age 17 in 1945. He underwent training at boot camp when World War II ended. He served for 44 years.

“After boot camp, I went to Florida for Scouts and Raiders school and then they dropped the bomb,” he said in the Marine Corps website interview.

He later headed to California and then China. In the ’50s and early ’60s, he was a member of the Underwater Demolition Team, after which he and 49 others were picked to join a new special unit the Navy was starting: the Navy SEALs.

He remained a SEAL with the special operations unit until 1988, and took part in two tours to Vietnam, earning a Bronze Star. He later joined the U.S. Special Operations Command and became the Command Master Chief for USSOCOM. He retired from the Navy in 1990.

In 1999, he interviewed to participate on Survivor.

“I read an article and it had the word challenge,” he said. “I didn’t know anything about the money, but I was going to do it anyway.”

“I figure they had 15 fouled-up people and they needed one normal one,” he added. “That was me.”