In the period of the Northern and Southern Courts, the family split into two families, the Kami Reizei family of Tameyuki REIZEI, the first son of Tamehiro REIZEI, and the Shimo Reizei family of Mochitame REIZEI, the second son of Temehiro REIZEI.
南北朝時代、冷泉為尹の長男冷泉為之の上冷泉家と、次男冷泉持為の下冷泉家に分かれた。