Under the Nine-Rank system,
九品中正制, proposed by
陈群 in 220 for
曹丕, an official called the
中正 ranked the men of his region in nine grades for office. It came to favour great clans, summed up as
上品无寒门,
下品无势族 'no poor families in the top grades, no great clans in the bottom', and gave way to the imperial examinations under the Sui.