Family Revolution of 1000: A term used by Joseph and Frances Gies to describe a fundamental change in the family after the year 1000 A.D. The progress of the family revolution varied from region to region with the political and economic situation. Previously the fluid horizontal kindred was grouped around a member who held power. It practiced partible inheritance and gave equal weight to maternal and paternal forebears. It identified itself merely by distinctive family first names. Now the family assumed a vertical dimension, firmly seated on an estate, a patrimony which descended from father to one son through impartible inheritance and which gave the family its new surname. --Eric Geckler