At the battle of Sekigahara in 1600, Geni MAEDA who had unwillingly joined the Western Forces was secretly in touch with Ieyasu and was given assurances that he would receive the domain after the battle; thus, the domain of Tanba-Kameyama was established.
慶長5年（1600年）、関ヶ原の戦いでは前田玄以はやむを得ず西軍に加わったが、家康に西軍の情報を内通していたため、戦後に家康より所領安堵を受け、ここに丹波亀山藩が成立した。