Each tribe was composed of a group of families, united by blood ties and constituting a social and political unit. As time went on, the stronger tribes tended to absorb the weaker ones. <ref>[http://encarta.msn.com/encnet/refpages/RefArticle.aspx?refid=762510356&vv=450 Twelve Tribes of Israel] MSN Encarta</ref> The Levi were to serve as religous for each tribe. | Each tribe was composed of a group of families, united by blood ties and constituting a social and political unit. As time went on, the stronger tribes tended to absorb the weaker ones. <ref>[http://encarta.msn.com/encnet/refpages/RefArticle.aspx?refid=762510356&vv=450 Twelve Tribes of Israel] MSN Encarta</ref> The Levi were to serve as religous for each tribe. |