tactics. Historian John Laband dismisses these stories as myth, writing: "What are we to make, then, of [European trader Henry Francis] Fynn's statement that once the Zulu army reached hard and stony ground in 1826, Shaka ordered sandals of ox-hide to be made for himself?" Laband also dismissed the idea of an march in a single day as ridiculous. He further claims that even though these stories have been repeated by "astonished and admiring white commentators," the Zulu army covered "no more than a day, and usually went only about ." Furthermore, Zulus under Shaka sometimes advanced more slowly. They spent two whole days recuperating in one instance, and on another they rested for a day and two nights before pursuing their enemy. Several other historians of the Zulu, and the Zulu military system, however, affirm the mobility rate of up to per day. Logistic support by youths Boys aged six and over joined Shaka's force as apprentice warriors (udibi) and served as carriers of rations, supplies like cooking pots and sleeping mats, and extra weapons until they joined the main ranks. It is sometimes held that such support was used more for very light forces designed to extract tribute in cattle and slaves from neighbouring groups. Nevertheless, the concept of "light" forces is questionable. The fast-moving Zulu raiding party, or "ibutho lempi," on a mission invariably travelled light, driving cattle as provisions on the hoof, and were not weighed down with heavy weapons and supply packs. Age-grade regimental system Age-grade groupings of various sorts were common in the Bantu culture of the day, and indeed are still important in much of Africa. Age grades were responsible for a variety of activities, from guarding the camp, to cattle herding, to certain rituals and ceremonies. Shaka organised various grades into regiments, and quartered them in special military kraals, with regiments having their own distinctive names and insignia. The regimental system clearly built on existing tribal cultural elements that could be adapted and shaped to fit an expansionist agenda. "Bull horn" formation Most historians credit Shaka with initial development of the famous "bull horn" formation. It was composed of three elements: The main force, the "chest," closed with the enemy impi and pinned it in position, engaging in melee combat. The warriors who comprised the "chest" were senior veterans. While the enemy impi was pinned by the "chest," the "horns" would flank