in the midst of all this , which happened during the first fifteen hundred years or so of the dark agesit was difficult to judge accurately when time had been mismanaged ; people had lost track of time for a while and did not know how many years had passed since coe pidaria was sealed , the major event by which calendar years were marked before and afterthe great creatures were decimated either by humans or by servants , most likely both , inadvertent casualties of warfare and hunting .