I meant, of course, that the meaning rather than the example dated to the 16th century, J! In fact, the earliest one recorded reads (modernised): "These merchants crack so much of themselves that I may also somewhat glory of myself."
As Grunty suggests, however, I've no doubt but that - even 'way back then - there were horsemen, for example, who scared ordinary punters whilst galloping through town. Old Will Shakespeare himself might have had occasion to exclaim to a companion in Stratford market-place: "Beware, good Launcelot, else yon speed merchant wilt have thee flatten�d!"