The then 22-year-old moved to Stamford Bridge after six Premier League seasons in West Ham United's first team.
Lampard went on to score a total of 211 goals in all competitions for Chelsea, which made him the club's all-time record goalscorer.
He won three Premier League titles and was named the Player of the Season in 2004/05. He also won both the UEFA Champions League and UEFA Europa League in his 13 years in the Chelsea midfield.
You can watch Lampard's best moments as a player in the video above and find out what else happened on this day by visiting the Premier League's new history section.
There you can also find retro club kits dating back to the competition's inaugural campaign and many other historical features, including past awards winners and reviews of every season.