No horse was going to save him.

Read the whole thing, as it’s very interesting, and jibes with what accounts of Bosworth I have read.

Of course, it bears pointing out that Richard fought like a mad boar at Bosworth, killing Henry Tudor’s standard bearer and very nearly getting to Henry himself before he was surrounded. Also, no contemporary source records the “My kingdom for a horse” line. Some traditions declare his last words to be “Treason!” but it’s entirely possible that he was given no chance to say anything at all.