Kaihatsu-ryoshu (local nobles who actually developed the land) is a generic name for those who secured a territory by extensive reclaimed land development after the mid Heian period, and who were originally influential peasants (Tato).
開発領主（かいほつりょうしゅ）とは、平安時代中期以降、墾田開発をさかんにおこなって領地を確保した者の総称であり、元来は有力農民（田堵）である。