I had other offers, but none convinced me as much as this one.Aitor Karanka
Karanka has been out of the professional game since leaving Nottingham Forest in January 2019.
Despite numerous offers from other clubs, he took his time to find what he believes is the right fit
"Since the first conversation with Dong (Ren, Blues CEO) I was convinced, and my time at home had finished," said Karanka.
"He told me of his passion, and I was waiting for that passion because after 18 months I felt that I should choose the right job.
"I had other offers, but none convinced me as much as this one."
Karanka admits it may take time to achieve the success he desires, but he is confident he can do good things.
"I'm not going to make the mistake that I made when I arrived at Middlesbrough when I said in my first press conference that I wanted to get promotion, and after a year and a half we got to final and we lost," he said.
"Although I thought that was a good season it became a failure.
"We just want to get as high as possible.
"In football you need to start with the foundations.
"I'd love to do what I did with Middlesbrough (get promoted) but you never know in football because it always so unpredictable.
"It was almost three years, but I'd love to do it in two years."
The former Real Madrid defender now has the difficult task of adding to his squad ahead of the season kick-off in early September.
Asked how many signings he was looking to make, Karanka said: "We've spoken briefly about players and we know what we want for the future.
“But we need to be really sure that the players that come here are ones that really want to come here.
"We are not just going to sign players quickly or because they are big names. We are not going to hurry."
Welcoming Karanka's arrival at the same press conference, Blues CEO Dong Ren expressed his delight in bringing the Spaniard to Blues.
"I'm absolutely confident we've got the right man," said Ren.
"The most important thing with this appointment is that Aitor will have the time and authority to build and lead this football club going forward.
"From the first time I called him I said 'Aitor, I'm not looking for someone to work for me or this football club, I'm looking for a proper partner with me to take this Club forward.
"He's the most the most humble person considering that many Champions League trophies and titles.
"He's a very down to earth guy. Every time he starts talking you listen. The more often we speak the more confident I am.
“Every decision about this football club will be made together. It's about team work not just on the football pitch.
"That teamwork starts with me and Aitor. Every decision will be discussed between us thoroughly.
"I'm very excited and can't wait to get started and he will have our backing for sure."