The Big Ten just got even bigger.

Pac-12 universities Oregon and Washington announced that they will join the Big Ten beginning in 2024, following an official invitation from Big Ten commissioner Tony Petitti Friday.

"The Big Ten is getting even bigger."

Welcome aboard, @GoDucks & @UWAthletics. pic.twitter.com/yNZ9SwdQs5

— Big Ten Network (@BigTenNetwork) August 4, 2023

The official announcement comes following several days of discussions about the future of the Pac-12 and the continued expansion of the Big Ten. ESPN’s Pete Thamel reported Thursday that Big Ten presidents authorized Petitti to explore adding the two schools to the conference.

Sources: The Big Ten’s presidents met early Thursday morning and authorized Commissioner Tony Petitti to explore expansion and bring them back more information on Oregon and Washington as potential Big Ten members. No offers have been made,

— Pete Thamel (@PeteThamel) August 3, 2023

Progression toward realignment and Big Ten expansion slowed drastically Friday morning, according to The Athletic’s Nicole Auerbach, but a deal was ultimately brokered Friday evening.

Oregon and Washington will join soon-to-be former Pac-12 schools USC and UCLA in Big Ten realignment after both schools announced the decision last summer. With the two additions of Oregon and Washington, the Big Ten will now include 18 universities.

After Colorado’s exit to the Big 12 and Utah, Arizona State, and Arizona’s reported flips to the same conference, according to The Athletic’s Max Olson, the Pac-12’s only firmly remaining schools are Cal, Stanford, Washington State, and Oregon State. With its broadcasting contract set to expire following the 2023-24 athletic year, the Pac-12 may collapse.

As a result of USC and UCLA joining, the Big Ten adjusted its football scheduling by abandoning divisions and adopting a format beginning in 2024 that guarantees each team plays at least twice in four years. The conference also added the “flex protect plus” model, which guarantees that certain rivalries are protected and played every season.

The conference released its 2024 and 2025 opponents in June with the aforementioned changes to the schedules, but with the additions of Oregon and Washington in the same years, there will likely be some adjustments made. ESPN’s Adam Rittenberg reported, however, that the schedules wouldn’t start “from scratch.”

The Big Ten won't be starting from scratch on new 2024-25 football schedules, I'm told. The base of what was announced, including preserving the most important games and maintaining frequency of matchups, will remain. Some adjustments needed to make 18 teams work. https://t.co/mLZ3EUph3Q

— Adam Rittenberg (@ESPNRittenberg) August 4, 2023

Both Oregon and Washington will enter the Big Ten with a combined 1-6 record against Penn State football. The Nittany Lions are 3-0 against Washington, and they most recently faced the Huskies in a 38-25 victory at the 2017 Playstation Fiesta Bowl.

Penn State’s last matchup against Oregon, meanwhile, was at the 1995 Rose Bowl, which the Nittany Lions won 38-20. The Nittany Lions are 3-1 against the Ducks.