In 1964, Arkle's first-place finish in the Cheltenham Gold Cup was the first big win by Ireland's most celebrated racehorse: the horse by which all others are measured. Fifty years on from the start of his incredible career - which included wins in the Cheltenham Gold Cup (three times), Irish Grand National, Hennessy Gold Cup, King George VI Chase and Punchestown Gold Cup - Anne Holland looks at Arkle's life and legend through the eyes of those who...