Abstract: A protective helmet (10) characterized in that it comprises a shell (12) shaped to fit about the head of a wearer, the shell (12) comprising an interior and an exterior, a forward region (14) intended in use to be situated adjacent a forehead of the wearer and a rearward region (22) situated at an opposite end of the shell (12) from the forward region (14), and the shell (12) also comprising a basal perimeter, a resilient liner (50) comprising an inner concave side arranged, in use, adjacent the head of the wearer, and an outer convex side adjacent the interior of the shell (12) one or more securing straps (34) attached to the basal perimeter and a locking means (80) to, in use, lockably secure each strap (34), the resilient liner (50) being formed by a shaping process so that a plurality of discrete chambers (58) is located within the liner (50) or between the resilient liner (50) and the shell (12), the resilient liner (50) and the chambers (58) being intended, in use, to absorb mechanical shock imparted to