The "Schutztruppe" recruited new personnel and expanded its size to some 14,000 soldiers, most of them Askaris. Lettow-Vorbeck's fluency in the Swahili language apparently earned the respect and admiration of his African soldiers. He appointed black officers and reportedly stated that "we are all Africans here". In one historian's opinion, "It is probable that no white commander of the era had so keen an appreciation of the African's worth not only as a fighting man but as a man."The historian Michael von Herff says the loyalty of Askaris during the campaign was due to them having formed a military caste within the colonial structure, which had largely separated itself from its members' tribal roots.