Describes the recovery of collagen breakdown products from a badly preserved bone from the site of Minshat Abu Omar, eastern Nile delta. The organic remains had been sealed into a hardly soluble mineral matter, which was the result of decomposition, recrystallization, and structural reorganization of the bone's mineral matrix. An explanation for the succession of protein degradation and preservation, including preferential loss of individual amino acids, is suggested. In addition, the results show that the term noncollagenous protein (NCP) is probably insufficiently defined for archaeological bone.