Graeme McDowell winning the 2010 U.S. Open at Pebble Beach was a source of pride for Northern Ireland. Rory McIlroy winning the U.S. Open at Congressional the following year with a record score was a source of hope.

And then a month later, Darren Clarke became the first Ulsterman in 64 years to raise the silver claret jug.

In a span of six majors, three champions came from a small country in the United Kingdom known for its castles, coastal links and three decades of religious and political violence known as "The Troubles."

What began as a question — "Could the British Open return to Royal Portrush?" — became a drumbeat until organizers found a way to make it work.

Golf's oldest championship returns to the Dunluce Links of Royal Portrush for the first time since 1951, the only occasion in 159 years that the British Open was not held in Scotland or England.

"I didn't see it getting big enough or sophisticated enough to host an Open," said David Feherty, who grew up in Northern Ireland and makes his return as part of the NBC Sports broadcast team. "It's just extraordinary what they've done."

The response to Royal Portrush hosting the British Open on July 18-21 for the first time in 68 years has been a combination of excitement and mystery.

The championship was a sellout 11 months ahead of time. The Royal & Ancient Golf Club decided in April to provide an additional 15,000 tickets for tournament days, and those were snatched up quickly. That means more than 200,000 spectators for the competition days of the 148th Open. And that should come as no surprise. Royal Portrush hosted the Irish Open in 2012 and drew 112,000 fans over four days, a European Tour record.

"I believe big-time sport needs big-time crowds," R&A chief Martin Slumbers said. "We're certainly going to get that."

And what will they see? That's the mystery.

The vast majority of the 156-man field — only 21 players were at the 2012 Irish Open — will be competing on the Harry Colt design for the first time. That included Francesco Molinari, the defending champion who will try to become the first back-to-back winner since Padraig Harrington in 2007-08.

Clarke still had possession of the claret jug when he returned to Portrush for the Irish Open and was paired with Molinari.

"Being paired with Darren the first round, it was something I still remember," Molinari said. "So I can only imagine what the Open is going to be. It is going to be even bigger, going back to Northern Ireland after so many years. Defending is always special, but defending in a place where the tournament has not been for so long I'm sure is going to be extra special."

There have been a few changes. To make it a large enough stage for the British Open, the R&A with approval from the club changed the routing. Martin Ebert, who consults on a half-dozen links in the Open rotation, took land from the Valley Links to build two new holes, Nos. 7 and 8. The original 17th and 18th holes are now used for the tented village. The nature of the links hasn't changed.

There are fewer bunkers than at most links courses because the contours and cliffs and dunes serve as a reasonable defense. The 16th hole is "Calamity Corner," where a shot over the ravine on the 236-yard par 3 that falls to the right could wind up 50 feet below the green.

Feherty recalls being there the first time he played with his father and almost didn't make it back up. "I almost had to rope myself to my dad and establish base camp," he said.

Ebert was profuse with his praise of Royal Portrush.

"It's hard to argue that this will be the finest piece of links land which The Open Championship is played," Ebert said in 2014 when the R&A announced a return to Portrush. "No other venue, I don't think, has such pure links undulations throughout its 18 holes."

McDowell is the only one of three major champions from this generation who actually grew up in Portrush, at Rathmore, the club next door. Even with a victory this year in the Dominican Republic, nothing was as satisfying as his 68 in the final round of the Canadian Open to earn a spot in the British Open. He could only dream of Royal Portrush getting another Open. It would have been a nightmare to miss it.

For McIlroy, the pressure might be greater than going for the career Grand Slam at the Masters.

He is the only two-time winner on the PGA Tour this year and is No. 3 in the world. He grew up in Holywood, but Royal Portrush feels like home. McIlroy was 16 when he set the course record of 61 at the North of Ireland Amateur.

"To have a round like that, do it there, have my dad watching, for me to shoot 61, was pretty cool," he said.

But this is big business. McIlroy is coming up on the five-year anniversary of his last major, far too long of a drought for his skill set. And he'll have the hopes of a golf-mad nation with him.

"I think one of the big things for me next week is to enjoy the experience," he said. "It might be 68 years until Portrush gets the Open (again), so go out and enjoy it. Look around. It's going to be such a great experience for me. The more I can enjoy that and roll with it and play with freedom, the better I think I can do."

Tiger Woods used to go to Ireland to prepare for the British Open. Now it's time to play, and there might be some rust. For the second time this year, Woods goes into a major championship without having played in a month. Since his victory at the Masters, the biggest buzz in golf this year, he has played three tournaments and 10 rounds.

Woods, who went to Thailand after a tie for 21st in the U.S. Open, posted a recent video from his home in Florida of waking at 1 a.m. to prepare for jet lag. The great preparation might be keeping it in play on a links that has a higher premium on accuracy than some other Open course.

Brooks Koepka will try to extend his amazing run in the majors — two victories and two runner-up finishes in the last four majors. He has never fared particularly well in links golf, which might be all the motivation he needs.

The Americans, meanwhile, will try to go for their first sweep of the majors since 1982, when Craig Stadler won the Masters, Tom Watson won the U.S. and British Opens and Raymond Floyd won the PGA Championship.

Until then, the intrigue is Royal Portrush.

"It's been a long time in the making," McIlroy said. "And obviously, everyone over there is so excited."