Forward Andreas Weimann has joined former Aston Villa team-mate Darren Bent at Derby after agreeing a four-year deal with the Rams.
Weimann has joined Paul Clement's ambitious side for an undisclosed fee, reported to be around £2.75million.
The 23-year-old has spent his entire senior career at Villa, barring two loan spells at Watford in 2011, making 129 appearances and scoring 24 times.
The Austria international was a peripheral figure under Tim Sherwood in the latter part of last season and is now ready for a change of scene.
"I'm excited to be here and I'm looking forward to the new challenge," he said.
"Derby has plans to be successful and get promoted and that's what attracted me here; I want to be part of that.
"The opportunity to play first-team football and drive the team to promotion is something that I want to do. I was at Aston Villa for eight years so I'm looking forward to this new stage in my career, although it will be a bit strange not being there."