After carving a superstar reputation for club and country and earning the moniker 'Saint' for his exploits, Iker Casillas suffered an unhappy end to his long Real Madrid career, whistled by the crowd that once adored him.

The club captain and goalkeeper, who is leaving after 25 years to join Porto, provided confidence and reliability at the back but what really made him into a fan favourite, before he fell out of favour, was his ability to pull off spectacular saves.

The 34-year-old, who joined Real's youth ranks aged 10 and spent 16 seasons in the first team, was widely criticised last season when the club failed to win a major trophy and while Casillas did not make glaring mistakes, he had clearly lost some of his powers.

Many questioned whether he deserved to be first choice in La Liga and the Champions League ahead of Costa Rica stopper Keylor Navas who was used only in King's Cup games.

The situation came to a head in May when Casillas was caught by television cameras answering back to disgruntled fans during a 2-2 home draw with Valencia.

It became a regular event at the Bernabeu for Casillas to receive some vitriol, particularly from the hard-core Real fans known as 'ultras'.

His problems started during Jose Mourinho’s final season as coach in 2012-13.

There was a widely reported power battle and Casillas was relegated to the bench, Diego Lopez taking his place.

Up until then Casillas had been the undisputed first choice for most of a career that saw him win three Champions League crowns and five La Liga titles.

A homegrown player, he made his debut for Real in September 1999, aged 18, and gradually cemented his place.

He shone on the international stage too, captaining Spain to European Championship triumphs in 2008 and 2012 and a maiden World Cup victory in 2010.

Casillas will be remembered for some decisive saves against Netherlands in the World Cup final, in particular to deny Arjen Robben on the way to a 1-0 win.

With the arrival of coach Carlo Ancelotti for the 2013-14 season, Casillas did not win his place back for La Liga games but played in the knockout competitions and helped Real to win the Champions League and King’s Cup.

Although he finished the club season on a high, he had a disappointing 2014 World Cup and made costly errors as Spain crashed out in the group stage.

In his last campaign for Real he was determined to hold off the challenge from Navas, with Lopez having moved to AC Milan.

TOUGH TASK

"The season before was tough and I knew this campaign was going to be the same," Casillas told Spanish radio recently.

"This was a challenge for me but at the same time I didn’t want to be a problem for the club.

"After 25 years what I want is to have a good understanding with the people who come to the stadium and those at home," added Casillas.

"For those people who whistled I can say that we have something in common that we both want the best for Madrid."

With the expected arrival of David De Gea from Manchester United soon, it would have been a battle too far for Casillas this time around.

A big-money move would logically make De Gea first choice and it would have been a tough task for Casillas to win his place back.

At his new Portuguese club he can enjoy regular football which should help him extend his Spain career at least until next year's European Championship in France.