A Who’s Who of Republican Party bigwigs will descend on Des Moines, Iowa, on Saturday for the Iowa Freedom Summit, an event hosted by Iowa Congressman Steve King and Citizens United, that is being billed as the first major GOP gathering in the Hawkeye State ahead of next year’s Iowa Caucuses. A number of possible 2016 hopefuls are scheduled to speak at the all-day conference, including Texas Sen. Ted Cruz, New Jersey Gov. Chris Christie and former Arkansas Gov. Mike Huckabee.

Here are five things to know about the Iowa Freedom Summit:

What is it?

The organizers are calling the Iowa Freedom Summit “a launch point for conservative ideas as we head towards [sic] 2016.” Conservative leaders are expected to speak about “how we can get America back on track by focusing on our core principles of pro-growth economics, social conservatism and a strong national defense.”

Instead of stump speeches, the 23 speakers will be having interview-style conversations with King, according to NPR. They will be limited to 20 minutes and the summit is expected to be an all-day event.

This is the first year the summit is being held. About 1,200 people are expected to attend, according to NPR.

Why does it matter?

Because a handful of Republicans who may be considering running for president are attending, and the Iowa Caucuses are nearly a year away. Besides Cruz, Christie and Huckabee, the summit will feature former Pennsylvania Sen. Rick Santorum, who won the caucuses in 2012 and ex-Texas Gov. Rick Perry.

"If you look at the list of attendees, you know that everybody is taking this event very seriously," David Bossie, one of the event’s organizers and president of Citizens United, told the Des Moines Register.

The Iowa Freedom Summit is also the first glimpse of a number of potential candidates at the same event. “The King event is significant. It's the kickoff for the cycle for Republicans,” Craig Robinson, a former political director of the Iowa Republican Party, told the Hill. “It's basically a year out, and it's going to be the first real time where Iowans are going to gather, look at these candidates side by side and really start deciding who they like.”

What should I look out for?

Since King is hosting the event, expect immigration to dominate the conversations. The Iowa congressman is one of the most vocal critics of President Barack Obama’s immigration policy, and he may be looking for guests to echo his stance, according to NPR.

Who is skipping it?

A few members of the establishment wing of the GOP will be no-shows, including ex-Florida Gov. Jeb Bush, Florida Sen. Marco Rubio and 2012 Republican presidential nominee Mitt Romney. U.S. Sen. Rand Paul, R-Ky., also won’t be attending. Bossie said the decision to skip the event may not play well with Iowans, who are known for wanting to have face-to-face time with candidates. "If you choose to not attend, you really don't know how Iowans will take that,” he said.

Who’s speaking?

Here’s a full list of speakers at the Iowa Freedom Summit:

U.S. Rep. Marsha Blackburn, R-Tenn

U.S. Rep. Rod Blum, R-Iowa

Former U.S. Ambassador to the United Nations John Bolton

Iowa Gov. Terry Branstad

Dr. Ben Carson

New Jersey Gov. Chris Christie

Texas Sen. Ted Cruz

Former South Carolina Sen. Jim DeMint

U.S. Rep. Jeff Duncan, R-S.C.

Iowa Sen. Joni Ernst

Former Hewlett-Packard CEO Carly Fiorina

Former Virginia Gov. Jim Gilmore

Former House Speaker Newt Gingrich

Iowa Sen. Charles Grassley

Former Arkansas Gov. Mike Huckabee

Utah Sen. Mike Lee

New Hampshire State Rep. William O'Brien

Former Alaska Gov. Sarah Palin

Former Texas Gov. Rick Perry

Iowa Lt. Gov. Kim Reynolds

Former Pennsylvania Sen. Rick Santorum

Donald Trump

Wisconsin Gov. Scott Walker