Petr Cech arrived in 2004 for £7 million, more than all the past goalkeepers in Chelsea history combined, with the task of challenging established number one Carlo Cudicini.
He immediately caught the eye with his height, incredible reaction speed and confidence in leaving his goal-line and began his Chelsea career as Jose Mourinho's first choice. He had to be good to keep Cudicini out.
A clean-sheet laden first season at Stamford Bridge was statistically the most accomplished by any Chelsea keeper - a run of 1,024 minutes without conceding a goal between December and March set a new English top flight record.
By the end of that season he had his first championship medal plus records for the fewest goals conceded and most clean sheets in an English top-flight season, recognised with the award of the Barclays Golden Gloves for 2004/05.
Though the 2005/06 version of the Chelsea defence was never quite as watertight as the season before, Petr continued to excel and was a major force in capturing a consecutive Premiership title.
Serious injury in October 2006 cast big doubts over the future of his career, but Petr overcame a fractured skull that had required immediate surgery, 30 stitches and much rest to return just three months later.
Within weeks he had recorded a seven-game run for club and country without conceding a goal, all while sporting the skull protection that has become a trade mark, and he ended the season with both domestic cups.
Injuries took their toll again during 2007/08, and change of management brought a change of goalkeeping coach - Christophe Lollichon, his coach at former club Rennes, joined the Blues - as Silvino Louro left with Mourinho.
Despite calf, hip and facial afflictions, 6ft 4in Petr was there as we reached the Champions League Final in Moscow, making a string of vital saves before we were eventually beaten on penalties by Manchester United - his save from Cristiano Ronaldo in the shootout proving academic.
After a typically consistent opening to the 2008/09 campaign, Petr's form, and those in front of him, took a dip around Christmas and new manager Luiz Felipe Scolari experimented with a set-piece zonal marking system which contributed to points being lost against Fulham and Manchester United, while we were nearly embarrassed in the FA Cup by Southend and then Ipswich.
Scolari's exit brought about an improvement in form under Guus Hiddink, the highlight of Petr's season coming in the Camp Nou as Barcelona were kept at bay, important saves made against Samuel Eto'o and Alex Hleb.
For the first season in three there were no major injury problems, with 35 Premier League appearances and an ever-present record in the Champions League.
In 2009/10 Petr further enhanced his own reputation with a solid season and a major contribution towards a first Premier League and FA Cup Double.
Individual errors were reduced, though a couple of mishaps occurred at Stoke and Aston Villa, but Petr bounced back to concede just two more in the next eight games as we entered the Christmas period on top of the league, and while a calf injury at the San Siro prevented him from participating in our Champions League second-leg defeat against Inter, causing him to miss five games, he returned for the run-in and had a big say in the direction the silverware went, earning the Premier League's Golden Glove on the final day of the season with his 17th clean sheet from 34 games.
Petr kept perhaps his best for last. In the FA Cup Final he first pulled off an amazing instinctive save to prevent Frederic Piquionne from opening the scoring, and then kept out Kevin-Prince Boateng's spot-kick with his feet, moments before Didier Drogba went up the other end and scored a superb free-kick.
Cech's next campaign began with a calf strain in pre-season, but he returned in time for the first league game and he would be an ever-present, surpassing the 300-appearance mark. He has since become Chelsea's highest appearing foreign player, going past Gianfranco Zola's 312. At the end of the season he was voted Chelsea's Player of the Year for the first time.
A knee injury hampered the early stages of 2011/12 causing him to miss two games, but he was soon back between the sticks, though facing criticism with goals flying past him. He was beaten five times by Arsenal in late October, the first time we had conceded as many since 2002, but if anyone has the strength of character to deal with such issues it is Cech, and he kept a clean sheet at Blackburn on Bonfire Night despite sustaining a broken nose in the early stages of the game, after a collision with his own defender Ashley Cole.
Since then he has been an ever-present in both league and cup, surviving the upheaval of Andre Villas-Boas's exit, and pulling off a string of crucial saves in big games, notably in the memorable extra time victory over Napoli at the Bridge that secured a Champions League last-eight place.
In the hunt for Champions League qualification for next season, the Czech international has also been integral, keeping Tottenham at bay with some superb stops and making his 50th appearance for club and country of the season in the 4-2 win at Aston Villa at the end of March.
As the Blues chased cup glory on two fronts, Cech was outstanding, making a stunning save from Andy Carroll in the FA Cup Final, as well as a number of crucial stops in the Champions League semi-final legs against Barcelona.
However, he saved his finest hour for when it mattered most, in the Champions League Final. Firstly, he saved an Arjen Robben penalty in extra-time with the score level at 1-1, while in the shoot-out he made successive stops from both Olic and Schweinsteiger to give us the advantage.
Cech was rewarded for his performances with the offer of a new four-year contract which he signed at the culmination of the season.
He made his 400th appearance for the club in the 2-1 win at Everton in December, 2012, although his involvement was brought to a premature halt when he was forced off at half-time after picking up an injury.
Cech was subsequently sidelined for three matches before making his return in the 4-0 win away at Stoke City. However, after picking up another injury, this time in training, Cech missed successive cup games against Swansea City and Brentford.
He made his return in the 3-2 defeat at Newcastle United, but after heading off on international duty shortly after the game, hurt his hand and returned to the club for treatment.
A precocious talent, Petr built his reputation at Sparta Prague where at the age of 19 he broke the national record for the longest spell without conceding a goal.
Equally hard to beat in the Champions League, over 1,000 minutes in all competitions passed without a goal.
That earned a move to Rennes in France where midway through his second season he agreed to join Chelsea for the next campaign on a five-year contract.
At Under 21 international level Petr was a major factor in the crowning of the Czech Republic as 2002 European Champions while at senior level, Euro 2004 brought five clean sheets, a semi-final and a place in Uefa's all-star squad of the tournament.
His reputation on the international stage continued to grow and he represented his country at both the World Cup in 2006, Czech Republic's first since splitting with Slovakia in 1993, and Euro 2008, where it was his unfortunate late error in the group stages that saw his country eliminated.
He bounced back to be named Czech Footballer of the Year for the fifth time in 2010 and although they failed to qualify for South Africa 2010, Petr continues as team captain.