This painting is one of a number in the Exhibition from the House of the Frescoes, excavated in 1923. It shows a man with two spears and others behind. Because of the dark skin tone of those behind, Evans regarded them as black mercenaries, with the man in front their captain. Given the fragmentary nature of the fresco this seems speculative.
Bibliography
Evans, Arthur. 1928. The Palace of Minos at Knossos, II, p. 755-757, pl. xiii
Myres, John (ed.). 1936. British Archaeological Discoveries in Greece and Crete 1886-1936, p. 26