Although the subject of probability is of such vital importance to insurance, no great detailed study was given to it until the sixteenth century. This was nearly two thousand years after the world's first insurance venture, that of Antimenes on behalf of Greek slave-owners against loss of their slaves (the early Greeks had also a good system of marine insurance). As in many fields of study, the early students of probability met with a great deal of opposition, which must have extended well into the nineteenth century, judging from the evidence of de Morgan's book of 1838.