In her 30 years of eventing, Mary King, 49, has won six team World and European Championship golds and four British Open titles, and has competed at five Olympic Games.
King will be Britain's oldest competitor at next year's London Games.
Tim Franks spoke to her about being a ruthlessly-driven competitor in a high-risk sport and the furious debate she provoked when she competed while five months pregnant.
You can watch the full interview on BBC World News on Tuesday 13th December at 00:30, 04:30, 15:30 and 21:30 GMT and on BBC News Channel on Tuesday 13th December at 04:30 and Wednesday 14th at 04:30 GMT.
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