When his stepfather stepped down at the age of 69 in 1988, O’Donnell, then 23, joined a team of riders who took turns as the Trojan warrior. O’Donnell has been the primary rider since 1998.

A Trojan warrior is likely to have worn a helmet of boar’s tusk sewn to a leather backing, and possibly wore bronze neck and shoulder guards, breastplate, or curiass, of bronze plates sewn ...