Some cataphracts fielded by the later Roman Empire were also equipped with heavy, lead-weight darts called "Martiobarbuli", akin to the plumbata used by late Roman infantry. These were to be hurled at the enemy lines during or just before a charge, to disorder the defensive formation immediately before the impact of the lances. With or without darts, a cataphract charge would usually be supported by some kind of missile troops (mounted or unmounted) placed on either flank of the enemy formation. Some armies formalised this tactic by deploying separate types of cataphract, the conventional, very heavily armored, bowless lancer for the primary charge and a dual purpose, lance-and-bow cataphract for supporting units.