Rafael van der Vaart maintains he was no "failure" at Real Madrid - but will not take a place in the Tottenham team for granted.
Spurs were able to complete the £8 million signing after the Premier League ratified the 11th-hour transfer deadline day move.
Van der Vaart, 27, appeared surplus to requirements at the Bernabeu, with Germany star Mesut Ozil having arrived in the summer, but the former Ajax and Hamburg star insists he has nothing to prove at White Hart Lane.
"I have not been a failure at Real Madrid," he said on talkSPORT. "I have always given my best over the last few years for both club and country. Now I have arrived at Tottenham and I want to show my quality.
"A number of clubs have been interested in me, but I always wanted to consider the best option at the last moment. When I saw that I would not be playing, I knew I had to leave.
"The Premier League is one of the best leagues in the world. I can only say if I have been worth the money at the end of the season."
He added: "I don't think I am going to have any problems adapting in England to the style of play and the country I am living in.
"The fact that Tottenham were playing in the Champions League influenced my decision a great deal. I have to earn my place in the team. Tottenham have a number of sensational players and I know it is not going to be easy, but that is the challenge I am looking forward to."
Tottenham also brought in former Arsenal defender William Gallas, Brazil defensive midfielder Sandro and, on loan, goalkeeper Stipe Pletikosa during the summer transfer window.
South Africa defender Bongani Khumalo had a trial with Spurs and it has been suggested the promising 23-year-old is set for a January move. However, his club SuperSport United maintain Spurs must up their interest or risk losing out to a rival.
SuperSport chairman Khulu Sibiya told the Sowetan newspaper: "This is not a foregone conclusion and Tottenham will have to pitch a new and better offer during the next transfer window. Negotiations will open then.
"I am of the opinion that the player has a lot of potential. If he is patient and concentrates on cementing his place in the national team, he will go far. I feel sure that in a few months Bongani's stature will have risen and he will secure himself an even better overseas move."