The original Greek term was used to refer to an authoritarian ruler with no pejorative connotations. But Plato and Aristotele did use it with a negative meaning implied, as they refered to a sovereign which does not make use of law to rule and hence is unjust and cruel to his subjetcs and others. Moreover, in ancient Greece, tyrants were influential individuals who had gathered enough support and people preferred them to rule over aristocrats, even tough they did not have legal rights to do so.
