OWINGS MILLS, Md. -- The Baltimore Ravens hired Mike Macdonald as their new defensive coordinator Thursday night, creating some team history in the process.

Macdonald, 34, becomes the youngest coordinator in the franchise's 26-year existence, taking over a defense that has built a reputation for ranking among the NFL's best. He is the youngest defensive coordinator in the league, per Elias Sports Bureau.

This also marks the first time the Ravens have hired a defensive coordinator outside the organization -- although this is more of a reunion. Working under both Harbaugh brothers -- going from Jim to John -- Macdonald was the University of Michigan defensive coordinator last season after coaching for seven seasons in Baltimore.

"Mike is one of us -- a Raven through and through," Baltimore coach John Harbaugh said in a statement. "During his initial seven seasons with us, it was evident that his leadership, intelligence and passion would earn him the opportunity to be a defensive coordinator in the NFL.

"Mike has continuously proven himself, including when he led one of the country's best defenses at Michigan last year. He is a proven play-caller who knows our system well. He also fully understands the standard of playing defense in Baltimore."

Macdonald replaces Don "Wink" Martindale, who was fired last Friday after a source said the sides couldn't agree on an extension. Under Martindale, Baltimore finished in the top 10 in defense in three of four seasons.

But Macdonald assumes control of a Ravens defense that ranked No. 25 in the NFL last season, when it lost three starters in the secondary (cornerbacks Marlon Humphrey and Marcus Peters along with safety DeShon Elliott). Struggling to generate turnovers and stop big plays, the Ravens allowed 363.4 yards per game, the second-most in team history.

Macdonald returns to Baltimore after a quick revitalization project at Michigan, which won its first Big Ten title in 17 years. In his only season as the Wolverines' defensive coordinator, Michigan finished No. 20 nationally in total defense (330.8 yards per game) after ranking No. 89 (434.4 yards) the previous season. Under Macdonald's guidance, edge rusher Aidan Hutchinson rose to a potential No. 1 overall draft pick after recording 14 sacks.

The official hiring of Macdonald came hours after the Ravens wrapped up their interviews for the position, but Macdonald was always considered one of the favorites to land the job. After losing out on the defensive coordinator position to Martindale in 2018, Macdonald was viewed as the heir apparent at defensive coordinator, even when he left for Michigan on the strength of Harbaugh's recommendation.

Macdonald joined the Ravens in 2014 as a 26-year-old intern before working his way up as a defensive assistant and a defensive backs coach. He coached the inside linebackers for his last three seasons in Baltimore.

Known for being detail-oriented and a good teacher, Macdonald was integral when the Ravens revamped their defensive scheme in 2018. He also drew praise for his work on the field, where he identified traits in players and where they can be moved around.

Harbaugh hired Macdonald after interviewing six other candidates for the job. Macdonald beat out two current Ravens coaches (defensive line coach Anthony Weaver and defensive pass game coordinator Chris Hewitt) as well as Jacksonville Jaguars defensive coordinator Joe Cullen, New Orleans Saints defensive backs coach Kris Richard, Dallas Cowboys defensive backs coach Joe Whitt Jr. and Tampa Bay Buccaneers inside linebackers coach Mike Caldwell.

Macdonald's introductory news conference is scheduled for Tuesday.