NOTRE DAME — Notre Dame will be playing in the national championship game in January.

That much everyone knows.

But if you’re just tuning in to Notre Dame’s historic season, you have some catching up to do. Here’s a quick look at what to know for the next few weeks leading up to the title game in Miami:

HOW DID THE IRISH GET THERE?

Despite starting the season unranked, Notre Dame broke into the Top 25 with a 50-10 win over Navy in Week 1.

With wins over ranked teams like Michigan State, Michigan, Stanford and Oklahoma, Notre Dame’s stock increased every week, and the Irish slowly climbed the charts.

At 9-0, Notre Dame was nestled at No. 3 in the Bowl Championship Series rankings alongside Alabama, Kansas State and Oregon. All three of those teams lost in a two-week span, vaulting undefeated Notre Dame to the No. 1 spot.

Backed by the top-ranked defense in the country, Notre Dame finished its regular season a perfect 12-0. The Irish will maintain their No. 1 status, which earns them a spot in the national championship game.

“You’re in the business to be around great kids because it’s collegiate athletics and the way it’s set up, only two teams can compete,” Irish coach Brian Kelly said after Saturday night’s win over USC. “So it feels great that you’ve got that opportunity to play for a national title.”

WHO WILL NOTRE DAME PLAY?

While Notre Dame is firmly in place as the No. 1 team in the national championship game, the No. 2 spot is less certain.

As of this week, it’s Alabama (11-1) who won last year’s title game and was No. 1 in the nation this season until it was stunned by Texas A&M in Week 10.

But Georgia (11-1) is ranked No. 3 and will face Alabama in the Southeastern Conference championship game on Saturday. The winner will face Notre Dame in Miami.

Alabama boasts the No. 1 scoring defense, No. 2 rushing defense and No. 3 passing defense in the country. Georgia ranks second in passing efficiency but otherwise doesn’t match up with Alabama statistically.

The Crimson Tide share four common opponents with the Bulldogs: Missouri, Auburn, Tennessee and Ole Miss. Both teams beat these opponents handily, the exception being Georgia’s narrow 51-44 win over Tennessee.

WHY IS THIS A BIG DEAL?

From a national point of view, Notre Dame was a once-perennial powerhouse that had fallen from grace in the past two decades. A berth in the national championship game points to a return to power for one of college football’s most storied programs.

From a Notre Dame point of view, this was a team that nearly everyone pegged as a 4- or 5-loss team this season. The Irish graduated their main offensive weapon, Michael Floyd, along with most of their secondary.

The defensive backs who remained were injured early in the season, leaving the backfield in the hands of a bunch of former receivers. To top it all off, Notre Dame was starting a redshirt freshman quarterback who had never played a down of college football.

Kelly said it’s hard to be surprised about how this season turned out, though.

“When I’m asked that question, it’s easy to say, ‘Yeah, I’m surprised,’” he said. “But when you go into that locker room and are around the guys I’m around, you’re not surprised. The commitment they’ve made, they’ve done everything I’ve asked them to do. It doesn’t surprise me anymore.”