Gwalior state was a semi-autonomous Maratha state. It was focused in modern-day Madhya Pradesh, arising due to the rise of the Maratha Empire and fragmentation of the Mughal Empire.
It was ruled by the House of Scindia, a Hindu Maratha dynasty and was entitled to a 21-gun salute when it became a princely state of the British Empire. The state took its name from the old town of Gwalior, which, although never the actual capital, was an important place because of its strategic location and the strength of its fort. The state was founded in the early 18th century by Ranoji Sindhia, as part of the Maratha Confederacy. The administration of Ujjain was assigned by Peshwa Bajirao I to his faithful commander Ranoji Shinde and his Sarsenapati was Yeshaji Aravandekar.The diwan of Ranoji Shinde(Scindia) was Ramchandra Baba Shenvi who was very wealthy he re-built the famous Shri Mahakala Temple in Ujjain during the 4th-5th decades of Eighteenth century AD.
Under Mahadji Sindhia (1761–1794) Gwalior State became a leading power in Central India, and dominated the affairs of the confederacy. The Anglo-Maratha Wars brought Gwalior State under British suzerainty, so that it became a princely state of the British Indian Empire. Gwalior was the largest state in the Central India Agency, under the political supervision of a Resident at Gwalior. In 1936, the Gwalior residency was separated from the Central India Agency, and made answerable directly to the Governor-General of India. After Indian Independence in 1947, the Sindhia rulers acceded to the new Union of India, and Gwalior state was absorbed into the new Indian state of Madhya Bharat.
The native states which issued postage stamps have been categorised as either convention states or feudatory states. The words ‘convention’ and ‘feudatory’ in this sense referred solely to postal arrangements with or in relation to British India.
In all, there were some 675 feudatory states at various times, but not all issued postal stamps and/or stationery. Many of the first issues were printed locally, using primitive methods such as typography and so they can be very rare. There was low quality of printing and design in many cases and collectors sometimes informally refer to them as “Uglies”. All remaining feudatory issues were replaced by stamps of the Republic of India on 1 April 1950 and most were declared obsolete from 1 May 1950 – there was one exception in the Anchal stamps of Travancore-Cochin which remained current until 1 July 1951.
There were six convention states: Chamba, Faridkot, Gwalior, Jind, Nabha and Patiala. They all used stamps of British India which were overprinted with the name of the state in Latin or Hindi/Urdu letters, or both. The Gibbons catalogue omits minor varieties of these stamps which had printing errors such as smaller letters, broken letters, unequal inking and unequal spacing. The convention issues were replaced by those of the Republic of India on 1 April 1950 but remained current until 31 December of that year, becoming obsolete from 1 January 1951.
* Text from Wikipedia