Under Carlo Ancelotti, Real Madrid finished with the LaLiga and Champions League Double last season.
Casillas enthused to AS: "In the last century, Real Madrid was the club that had the hegemony of the old European Cup; in this century it is Real Madrid which continues to have the hegemony of the Champions League.
"It is back to where it has always been, it is a reference, the best club in the world, thanks to the image it gives, to all the titles it obtains, despite the players who come and go. Real is the best team for the people who work there, for the DNA, for everything that has been passed on over the years. I remember that twenty years ago people didn't like the transfer, while now everyone wants to come play for Real Madrid.
"They're, not just one step, but ten (ahead of rivals). Real Madrid is at the top of the building at the moment, the others are in the centre."
He added on Ancelotti, "I believe that Carlo is the architect of everything that has been achieved. He has good players but it is not easy to deal with all the injuries he has had this season.
"It should be remembered that Militao was practically the best central defender last year of Europe. He has had significant losses and has known very well how to manage each player. This is the case, for example, of Kroos or Modric, who are veterans who perhaps cannot express themselves at their best in two close matches."