Tony Docherty says "this day was always going to come" after agreeing to manage Dundee and ending his long standing partnership with Derek McInnes.
The 52-year-old replaces Gary Bowyer, who was a surprise departure after leading his side to the Championship title in his first season in charge.
Docherty assisted McInnes at St Johnstone, Bristol City, Aberdeen and latterly at Kilmarnock.
"I've got a real gut feeling about it," Docherty said of the Dens Park job.
"Derek is a really really close friend of mine. He's fully supportive, it's totally amicable.
"I have had opportunities before, but this opportunity feels right for me. I've had over 750 games as an assistant now, a long time. I just felt the time was right for me now to go and be my main man, and me to call the shots.
"One of the things I've picked up in my career, and actually from Walter Smith when I was doing my pro licence with him, is go with your gut, and the gut feeling for this one feels right. There's exciting times."
Dundee technical director Gordon Strachan knows Docherty from their Scotland days and Docherty explained he had "kept in touch with Gordon on a regular basis".
"I've worked with a lot of managers," Docherty said. "I've been involved in European competitions, I've been involved in the national team, I worked in the English Championship, the Scottish Premiership, so I've taken a bit of everyone.
"What I will bring is a passion. I'll bring an authenticity and what I'll definitely bring is a work ethic. What you get from a new manager is you get the hunger, the motivation, the desire to prove people wrong.
"You're getting all that with me, but you're also getting the experience behind it, the knowledge behind it, and hopefully Dundee FC will see the benefit of that."
Docherty spent an extended spell living in Dundee and feels privileged to be following in the footsteps of Bob Shankly, Tommy Campbell, Jim Duffy, Archie Knox and Jocky Scott.
And, on recruitment, the new manager commented: "If I get the blend right with that young talented hungry footballer and that good experienced, good pros that have been there know how to bring on young ones.
"They'll carry on my message when I walk out the room, that's what I want."
Docherty's last act as Kilmarnock assistant was to help McInnes steer the Ayrshire side clear of relegation with a 3-1 win over Ross County on Sunday.
The former midfielder spent his playing career in Scotland's lower leagues with Stirling Albion, East Stirlingshire and Albion Rovers, where he also became Scottish FA development officer for the Glasgow area before a move to Falkirk as community coach.
He was promoted to assistant manager by Ian McCall, who Docherty followed to Dundee United before switching to St Johnstone to work under McInnes for the first time in 2007.
In between time spent with McInnes at Aberdeen and Kilmarnock, he also had a spell as assistant with Forfar Athletic.
Dundee managing director John Nelms praised Docherty's "wealth of knowledge of our game" and McInnes congratulated Docherty on his new job.
"Living in the area, he knows the full potential of Dundee FC," he told Kilmarnock's website.
"One a personal note, I would like to thank Tony for his help and immense loyalty over all of the years we have worked together and wish him well in his new challenge."