The state was administered as part of the Bundelkhand Agency of Central India.
Its capital was Samshergarh town, located in a level plain in the Bundelkhand region crossed by the Pahuj and the Betwa rivers.
The founder was Ranjith Singh who in 1760, profiting from the troubled times of the Maratha invasion, proclaimed his state independent and was acknowledged as a Raja by the Marathas.
In 1817 Samthar was recognized as a state by the British.
In 1884 the state had to cede some territories for the construction of the railways.