Former circuit judge, legislator and University of Hawai'i regent Ambrose Rosehill, known for his tough nature on the bench and his role in the state Republican Party, has died He was 79.

Rosehill, a veteran of the Korean War, celebrated his birthday on Saturday at a gathering of about 40 friends and relatives in Waimanalo. His son Adrian Rosehill, 51, said his father was in good spirits, excited to see friends he hadn't seen in a while, making his death on Sunday a shock.

"He had such a brilliant mind. He was always a fair person. When he was on the bench, he always gave careful consideration to how he would rule," his son said.

The elder Rosehill had been battling throat cancer since December 2005. His death was apparently due to natural causes.

Upon graduating from Kamehameha Schools in 1944 at the age of 16, Rosehill was told that he "wasn't college material," said Adrian Rosehill, a Honolulu attorney.

"But my dad wouldn't accept that," he said.

By age 22 he had earned bachelor's and master's degrees from Stanford University, his law degree from Georgetown University and had been admitted to the Hawai'i Bar Association.

The young Honolulu attorney was an up-and-coming GOP star and hoped to breathe new life into the Republican Party with his more independent-leaning ideas. He ran his first campaign for the Territorial Legislature in 1958, along with a group of other young and ambitious Republicans, none of whom had much financial backing.

He won and was re-elected three times.

Rosehill, who would often conduct business with a cigar hanging out of his mouth, was considered one of the most educated members of the Territorial Legislature, and later the state Legislature, and a potential contender for a congressional seat.

Rosehill was a vocal opponent of budget cuts, saying they would hurt social services, and he introduced a series of tax relief proposals in the Legislature.

"To this day, he was a strong Republican," Adrian Rosehill said.

In 1965 he lost a re-election bid, but he went on to serve as a commissioner of the state Department of Land and Natural Resources, chairman of the city's Liquor Commission, the Reapportionment Commission and the University of Hawai'i board of regents. He was also a deputy attorney general for the Territory of Hawai'i and a deputy attorney for the City and County of Honolulu.

Adrian Rosehill recalled that his father was a champion for education.

"He enjoyed being on the board of regents for that very reason," he said. "He always thought the university should be an excellent institution in Hawai'i."

He always encouraged his children to seek as much schooling as possible, Adrian Rosehill said.

"A lot of this came from when he was told that he wasn't worthy of higher education. He was a strong believer in the value of education," he said.

The elder Rosehill spent the last 12 years of his career as a district court judge, retiring in 1997.

He is survived by brother, Richard Rosehill; children, Betty-Anne Rosehill-Ulsh, Alan T. Rosehill and Adrian W. Rosehill; stepchildren, Giles "Skip" Florence, Robyn Jones, Allyson Johnson and Stacy Rosehill; six grandchildren; and two great-grandchildren.

Services will be held at 8:30 a.m. Sept. 29 at the Outrigger Canoe Club. His ashes will be scattered in the ocean off the Outrigger. Aloha attire is requested. In lieu of flowers, the family requests that donations be sent to the Friends of Iolani Palace.

Reach Loren Moreno at lmoreno@honoluluadvertiser.com.