Thanks for the concise response. But one question remains is why can they have relations with their slaves, intimately? And why would islam allow slavery if we should all be slaves to Allah and no other?
Bacially 1400 yrs ago slavery was just a everyday practise, way of life, a bussiness, just like people go work today, people worked as slaves and in return their masters (employers) gave in return food and shelter as poverty was just a fact of life for many back then who had little or nothing. Now when islam came for the new religion to say slaverly is haram it would have been met with 100% opposition, its like scientists saying pollution is dangerous so everycountry needs to make it haram. So instead what the new religion did is 1st establish that all human beings are equal on a general level, thus a slave was equal to his master in reality, and was a slave to his master only from a worldly point not from a religious, spiritual point. 2nd gave slaves rights eg food, clothing, relgious, human rights that their masters must observe. 3rd made freeing slaves a great major good deed thus encouraging slaverly to slowly end. As for having relations with ones' slave' this is related to the cultural, social and political situation of the times. As many slaves were gained through war and it served as increasing in number.