Water is a major theme on Day Four with key events at the Aquatics Centre and at Lee Valley. Beijing gold medal swimming sensation Michael Phelps could equal Russian gymnast Larisa Latynina's record tally of 18 Olympic medals when he takes part in the 200m butterfly and the 4x200m freestyle relay in the pool in another thrilling evening. Glamorous Italian swimmer Federica Pellegrini will be one favourites for the women's 200m freestyle and there's also the small matter of the women's 200m individual medley final. Earlier in the day, British pair Tonia Couch and Sarah Barrow, the European Champions, take part in the 10m platform synchro in the diving pool while David Florence is GB's hopes in the men's canoe slalom at Lee Valley. In non-water-based sports, Zara Phillips will target a medal in her grandmother's Diamond Jubilee year in the equestrian team eventing at Greenwich Park. Mary King – the oldest home female competitor at 51 – competes in her sixth Olympics while William Fox-Pitt targets gold in the individual eventing jumping. Over at Wimbledon, both Andy Murray and Roger Federer are in action; Great Britain take on Brazil in women's football at the City of Coventry Stadium, while all eyes will be on the North Greenwich Arena for the women's team gymnastics final. At the ExCeL Centre, Richard Kruse hopes to end Britain's 48-year wait for an Olympic fencing medal in the men's individual foil fencing.
Gold medals up for grabs: 15
Today's medal sports: equestrian, shooting, diving, canoe slalom, weightlifting, judo, artistic gymnastics, swimming, fencing