Kate the Great makes it eight (world records)

From the day at age 15 she became the surprise gold medalist in the 800-meter freestyle at the 2012 London Olympics, where Michael Phelps’ successful quest to be the most decorated Olympian in history was the big story, there seemed little doubt Katie Ledecky was destined for a much higher profile as the next Summer Games approached.

Now there seems no doubt Ledecky, of Bethesda, Md., will be one of the biggest stars in Rio a year from now -- and perhaps be acclaimed the greatest women’s distance swimmer in history.

You already can call her Kate the Great.

Less than a day after winning her second straight world title in the 400 freestyle, with a time that tickled her world record at that distance, Ledecky broke her own 1,500 free world record.

In the preliminaries.

Ledecky’s time of 15 minutes, 27.71 seconds Monday morning at the world meet in Kazan, Russia, took .65 seconds off the mark she had set at last year’s Pan Pacific Championships.

“I was barely focusing on this morning’s swim,” Ledecky said. “I was just so relaxed. It’s probably one of the coolest world records I’ve broken.”

It was her fourth career world record in the 1,500 and eighth overall, including two each in the 400 and 800.

The final is Tuesday night. She is the defending champion.

“I think breaking that record is just a testament to the work I’ve been doing and the kind of shape I’m in right now,” she said. “It’s kind of a shock.”

The Stanford-bound Ledecky, who is deferring her matriculation until after the 2016 Olympics, also is to swim the 800 and 200 freestyles and a leg on the 4 x 200 free relay. Should she make the 200 free semis, that race would be less than a half hour after the 1500 free final.

Phelps, by the way, had qualified for worlds but gave up his place as part of the punishment deal with USA Swimming after his drunken driving arrest last fall.

In other action Monday:

Winnetka’s Conor Dwyer had swum a strong anchor leg (48.44 seconds) in Sunday’s prelims of the 400 free relay, but subpar performances from the opening two swimmers meant the U.S. men missed the final for just the second time in world meet history.

-- Reigning world and Olympic 100 backstroke champion Matt Grevers, of Lake Forest and Northwestern, had the third fastest time (52.73) in Monday’ night’s semifinals, behind Mitchell Larkin of Australia (52.38) and Camille Lacourt of France (52.70.) The final is Tuesday night.

-- Dwyer, reigning world silver medalist in the 200 free, failed to make Tuesday’s eight-swimmer final. Dwyer was ninth in 1 minute, 46.64 seconds, .21 from the final spot. Ryan Lochte, the 2011 champion, was the fastest semifinalist at 1:45.36.

-- Missy Franklin, reigning world and Olympic champion in the 100 back, was fifth fastest qualifier (59.59) for Tuesday’s final in that event.