In the traditional Mongolian family, each son received a part of the family herd as he married, with the elder son receiving more than the younger son. The youngest son would remain in the parental tent caring for his parents, and after their death he would inherit the parental tent in addition to his own part of the herd. This inheritance system was mandated by law codes such as the Yassa, created by Genghis Khan. Likewise, each son inherited a part of the family's camping lands and pastures, with the elder son receiving more than the younger son. The eldest son inherited the farthest camping lands and pastures, and each son in turn inherited camping lands and pastures closer to the family tent until the youngest son inherited the camping lands and pastures immediately surrounding the family tent. Family units would often remain near each other and in close cooperation, though extended families would inevitably break up after a few generations. It is probable that the Yasa simply put into written law the principles of customary law. Nilgün Dalkesen wrote in "Gender Roles and Women's Status in Central Asia and Anatolia between the Thirteenth and Sixteenth Centuries": "It is apparent that in many cases, for example in family instructions, the yasa tacitly accepted the principles of customary law and avoided any interference with them. For example, Riasanovsky said that killing the man or the woman in case of adultery is a good illustration. Yasa permitted the institutions of polygamy and concubinage so characteristic of southerly nomadic peoples. Children born of concubines were legitimate. Seniority of children derived their status from their mother. Eldest son received more than the youngest after the death of father. But the latter inherited the household of the father. Children of concubines also received a share in the inheritance, in accordance with the instructions of their father (or with custom)"