The Mahi Kantha Agency was a political office of the British Empire in India that administered a collection of princely states of India, in the Gujarat Division of Bombay Presidency. Idar State was the major princely state in the territory and covered almost half of the Agency. Apart from this, there were other 11 princely states like Mohanpur, Malpur, Danta, Pol State and the princely state of Ambliara, also known as Amliara or Amliyara. It also included several estates that belonged to the Rajputs or Thakurs formerly feudatories of Baroda. Most of the states paid tribute to Baroda State; while some of the regions were recognized as non-jurisdictional talukdars, which were under the administration of the British Government of India. The Mahi Kantha Agency covered a total area of 8,094 sq km. According to the 1901 Census, the total population of the territory was 361,545. The region was severely affected by the famine during the years 1899- 1900. As a result of the famine the population of the Indian princely states in the Agency decreased by 38 per cent during this period.
A metre gauge railway was commenced in 1897 from Ahmedabad to Ahmednagar, through Parantij near the princely state of Ambliara. The Scott College, which was modeled on British public schools, was located at Sadra, where the sons of the native rulers or Indian Princes received education. There were other English language institutes and schools at Mansa Sadra and Idar. After the Second Anglo Maratha War that occurred during 1803- 1805, the states came under the British dominion and administration. After the decline of the Maratha Empire, in the year 1811, the British East India Company stipulated to collect and pay the yearly tribute of the Mahi Kantha states, over to the ruler of the princely state of Baroda.
Later in the year 1820, the British took over the administration of the entire territory approving to collect and pay over the tribute free of expense to Baroda, while the state of Baroda was pledged not to interfere with the management and administration or to send troops. During the 1830s, and later in 1857 and 1867, a few disturbances occurred in the region and the Mahi Kantha Agency remained in peace until the year 1881, when the Bhils of Pol state revolted against their chief and extracted a settlement of their claims from the chief.
The princely states in the Mahi Kantha Agency acceded to the newly formed Union of India after the nation attained independence from the British Government of India. The territory was reorganized and restructured into districts of Bombay State. In the year 1960, the Indian state of Bombay was divided along linguistic lines, and the region of Mahi Kantha was incorporated as a part of the newly formed state of Gujarat.