1985: Born May 25, in Sevres, France.
2004: Spends five months at Watford but does not do enough to earn a full-time contract with the club.
2005: Signed by Rouen and converted from a midfielder to a striker.
2006: Moves to Belgian side Mouscron but breaks two bones in his leg after scoring in each of his first three games, with the subsequent surgery leading to permanent knee damage.
2007: June 2 - Makes a goalscoring start to his international career with Senegal, scoring in a 1-1 draw with Tanzania.
August - Joins Hoffenheim and helps the club gain promotion to the Bundesliga in his first season.
2009: A proposed move to Stuttgart collapses when Ba fails his medical due to the knee damage suffered in 2006.
2011: January - Another failed medical prevents a move to Barclays Premier League side Stoke, but instead completes a deal to join West Ham on a pay-as-you-play deal.
May - Scores seven goals in 13 games for the Hammers but turns down a new deal when the club are relegated to the npower Championship, triggering a clause in his contract that allows him to negotiate a free transfer away from Upton Park.
June 17 - Newcastle win the race to sign Ba, who signs a three-year deal.
September 24 - Scores first goals for Newcastle with a hat-trick against Blackburn.
December - Named Barclays Premier League player of the month.
2012: March - Voted the best Premier League signing of the season by the league's managers but does not score again for the remainder of the season.
2013: January 2 - European champions Chelsea invoke a minimum-fee release clause in Ba's contract to allow talks between the club and the player's representatives.
January 4 - Signs for Chelsea in a three-and-a-half-year deal for an undisclosed fee.