History is the study of the past, particularly the written record of the human race but more generally including scientific and archaeological discoveries about the past, Recently there has been an increased interest in oral histories nad traditions, passed down from generation to generation verbally, Since historians are simultaneously observers of and participants in the historical process the historical works they produce are written from the perspective of their own time and sometimes with due conked possible lessons for their own future in the words of Benedetti Croce ''All history is contemporary history'' . Many historians are employed at universities and other facilities for post secondary education In addition, it is common, Although not required, for many historians to have a Doctor Of philosophy (Ph. D ) Degree in although not required for many historians to have a Doctor of Philosophy (Ph.D) degree in their chosen areas of study The Books (in three volumes) contain the life and work of world Great Historians.