<P> In ancient times , tribal nations preferred endogamous marriage -- marriage to one 's relatives ; the ideal marriage was usually that to a cousin , and it was often forbidden for an eldest daughter to even marry outside the family . Marriage to a half - sister , for example , is considered incest by most nations today , but was common behaviour for Egyptian pharaohs ; similarly , the Book of Genesis portrays Sarah as marrying Abraham , her half - brother , without criticising the close genetic relationship between them , and the Book of Samuel treats the marriage of a royal prince to his half - sister as unusual , rather than wicked . </P>
<P> In ancient times , tribal nations preferred endogamous marriage -- marriage to one 's relatives ; the ideal marriage was usually that to a cousin , and it was often forbidden for an eldest daughter to even marry outside the family . Marriage to a half - sister , for example , is considered incest by most nations today , but was common behaviour for Egyptian pharaohs ; similarly , the Book of Genesis portrays Sarah as marrying Abraham , her half - brother , without criticising the close genetic relationship between them , and the Book of Samuel treats the marriage of a royal prince to his half - sister as unusual , rather than wicked . </P>
who married their half sister in the bible
who married their half sister in the bible
Abraham
Abraham