The Ghanian hailed his former boss at Stamford Bridge, saying that his relationship with the Portuguese manager was the main reason behind his move to La Liga
The pair originally worked together in London when the Portuguese trainer brought Essien to Stamford Bridge from Lyon in 2005 and the midfielder is now relishing the opportunity to work under his former mentor again.
"Everything happened so fast," reflected the 29-year-old at a press conference. "Mourinho called me and said he was ready to take me. I said yes immediately."
"That was more than enough for me to come here. I see him as a father because he was the one responsible for my move to Chelsea. We have a very good relationship, with a clear understanding of each other."
Essien has enjoyed several injury-laden campaigns at Stamford Bridge in recent years, struggling to only 14 appearances last season, something he is keen to change.
He added: "I have had some fitness problems in the past, but I'm strong. If I wasn't ready to play here in the first place, I wouldn't have signed on.
"Real Madrid have very, very good players, but I'm ready to feature anywhere Mourinho asks me to. It'll be a great feeling to win titles this way."