Royal, who won two national championships and turned the Longhorns into a national power, died early Wednesday at age 88 of complications from cardiovascular disease, school spokesman Bill Little said. Royal also suffered from Alzheimer's disease.
Royal didn't have a single losing season in his 23 years as a head coach at Texas, Mississippi State and Washington. Known for their stout defenses and punishing running attacks, his Texas teams boasted a 167-47-5 record from 1957-1976, the best mark in the nation over that period.
"It was fun," Royal told The Associated Press in 2007. "All the days I was coaching at Texas, I knew this would be my last coaching job. I knew it when I got here."
It almost didn't happen. Royal wasn't Texas' first choice.
Texas was coming off a 1-9 season in 1956 -- still the worst in program history -- and wanted a high-profile coach to turn things around. The Longhorns were rebuffed by Georgia Tech's Bobby Dodd and Michigan State's Duffy Daugherty, but both coaches encouraged Texas to hire the 32-year-old Royal, who was lying in bed the night he got the call summoning him to Austin.
"Edith, this is it, this is the University of Texas," Royal told his wife.
Royal led the Longhorns to a 6-3-1 record in his first season, but he was so sickened by Mississippi's 39-7 thrashing of his team in the Sugar Bowl that he gave away the commemorative bowl watch he received.
Under Royal, Texas won 11 Southwest Conference titles, 10 Cotton Bowl championships and national championships in 1963 and 1969, going 11-0 each time. The Longhorns also won a share of the 1970 national title, earning him a national stature that rivaled that of Alabama's Paul "Bear" Bryant and Ohio State's Woody Hayes. Royal was inducted into the College Football Hall of Fame in 1983.
A public memorial ceremony is scheduled for noon Tuesday at the Frank Erwin Center basketball arena. Royal will be buried at the Texas State Cemetery in Austin, an honor typically reserved for the state's military and political leaders.
On Saturday, the Longhorns will honor Royal at their home game against Iowa State by wearing "DKR" stickers on their helmets and by lining up in the wishbone formation, which Royal used to such great success, for their first offensive snap.
"Today is a very sad day. I lost a wonderful friend, a mentor, a confidant and my hero. College football lost maybe its best ever and the world lost a great man," current Texas coach Mack Brown said Wednesday. "His counsel and friendship meant a lot to me before I came to Texas, but it's been my guiding light for my 15 years here."
As a player at Oklahoma, Royal was a standout quarterback, defensive back and punter, and he credited hard work and luck for his success on the field and later as a coach. He had a self-deprecating style and a knack for delivering pithy quotes -- or "Royalisms" -- about his team and opponents.
"Football doesn't build character, it eliminates the weak ones," was one of Royal's famous lines.
"Luck is when preparation meets opportunity," was another.
"He was a guy who was so strong and so determined and so direct about things," said former Texas quarterback James Street. "He was that way to the very end."
Royal and assistant Emory Ballard changed the football landscape in 1968 with the development of the wishbone, which features a fullback lined up behind the quarterback and a step in front of two other backs.
The innovation nearly flopped. After a tie and loss in the first two games that season, a frustrated Royal inserted backup Street to take over.
"Coach Royal grabbed me and he looked for a minute as if he were having second thoughts about putting me in. Then he looked me straight in the eye and said, `Hell, you can't do any worse. Get in there,"' Street said
Texas won its next 30 games. Soon, rival Oklahoma and other schools started using the wishbone as well.
"The University of Oklahoma joins the rest of the nation in celebrating the life's work of Darrell Royal," said Oklahoma athletic director Joe Castiglione. "We've truly lost an icon -- a champion, an innovator and an educator."
The national title season in 1969 included what was dubbed the "Game of the Century," a come-from-behind, 15-14 victory by the top-ranked Longhorns over No. 2 Arkansas to cap the regular season.
In Texas lore, it ranks as the greatest game ever played. President Richard Nixon, an avid football fan, flew in by helicopter to watch. Afterward, Nixon greeted Royal with a plaque in the Texas locker room proclaiming Texas the national champion.
The Longhorns also were named national champions by United Press International in 1970, a year in which Texas lost its final game to Notre Dame in the Cotton Bowl and finished 10-1.
Royal faced criticism over the lack of black players on his first 13 Texas teams, although he had coached black players at Washington and in the Canadian football league.
At the 1960 Cotton Bowl, Syracuse accused Texas of hurling racial barbs at Syracuse's black players, which Royal denied. Texas became the first SWC school to announce it would fully integrate the athletic program in 1963, but the football team didn't have a black letterman until Julius Whittier in 1970.
Royal, who acknowledged being unconcerned about racial discrimination for much of his life, credited former President Lyndon B. Johnson with turning around his viewpoint. Johnson, who attended Texas football games after his presidency ended, was close friends with Royal.
"I'm not a football fan," Johnson once said. "But I am a fan of people, and I am a Darrell Royal fan because he is the rarest of human beings."
In 1972, former Texas lineman Gary Shaw published "Meat on the Hoof," a searing critique of the Texas program that accused the coaches of having a class system within the program and of devising sadistic drills to drive off unwanted players. Royal tried to distance himself from the claims, saying in interviews he had "never heard" of the drills Shaw described.
"I want to be remembered as a winning coach, but also as an honest and ethical coach," Royal said in 1975.
Royal was among the first football coaches in the nation to hire an academic counselor -- sometimes referred to as a "brain coach" in that era -- to ensure athletes went on to graduate. He also set aside a fund for a special "T" ring, which players received upon graduation. Royal also served as Texas athletic director from 1962-1979.
The youngest of six children born to Katy and B.R. "Burley" Royal, he grew up in tiny Hollis, Okla., where he chopped cotton as a young boy for 10-cents an hour to help his family through the Depression. His mother died before he was 6 months old, and he lost two sisters to a fever epidemic.
In 1938, Royal's father took the family from the Dustbowl to California to look for work. Homesick for Oklahoma, Royal soon packed his bags and hitchhiked his way back.
Royal is survived by his wife, Edith, and a son, Mack. The couple had two other children, daughter Marian, who died in 1973, and son David, who died in 1982.