The Eastern States Agency comprised princely states like Cooch Behar (in West Bengal), Mayurbhanj (in Orissa), Tripura in the North-East, Surguja (in Chhattisgarh), and many others.
These states had very modest-sized armies, but some of them also contributed men and material to the Imperial Service Troops.
In southern India, the infantry battalions of Mysore, Travancore, and Cochin princely states were amalgamated into the Madras Regiment.
The 1st Travancore Nair Infantry, tracing it's origins to 1741 and the Battle of Colachel, became the 9th battalion of the Madras Regiment, while the 2nd Travancore Nair Infantry became the 16th battalion.
An infantry battalion from the Cochin State Forces became the 17th battalion.
The 1st battalion Mysore State Infantry formed the core of the 18th battalion, but men from the other two battalions of the State Forces were also amalgamated.
Following the success of Operation Polo and the annexation of Hyderabad into the Indian Union, all the fifteen battalions of the Hyderabad State Forces were disbanded except for the 2nd Hyderabad Infantry, which carried the honours of Hyderabad.
This unit was re-designated as the 22nd battalion of the Maratha Light Infantry and still comprises 50% Muslim and 50% Maratha soldiers in its ranks.
In northern India, the State Forces of Jammu and Kashmir, fought well and withstood many a siege, during the Pakistani invasion of J&K State and were hence merged wholesale as a distinct regiment, the Jammu and Kashmir Rifles, into the Indian Army.
Dogra recruits from the armies of princely states in neighboring Himachal Pradesh formed the 16th battalion of the Dogra Regiment.
From the armies of the Sikh princely states, 1st Jind Infantry became the 13th battalion of the Punjab Regiment, the 1st Nabha Akal Infantry became the 14th, the 1st Patiala Rajinder Sikh Infantry became the 15th, and the 2nd Patiala Yadvinder Infantry became the 16th.
The biggest concentration of princely states was in modern Rajasthan, Gujarat, and Madhya Pradesh.
After Independence the 4th Gwalior Infantry became the 14th Kumaon Regiment while the Indore Infantry was designated as 15th Kumaon.
Personnel of the Kutch State Forces and from the princely states in Saurasthra, were organized into the 7th Grenadiers.
Saurashtra Infantry also became the 18th Rajputana Rifles.
The Sawai Man Guards of Jaipur State, was engaged in fighting in the J&K War, and became the 17th battalion of the Rajputana Rifles.
Mewar the greatest state in Rajputana contributed the 1st Mewar Infantry, which became the 9th battalion of the Grenadiers Regiment.
A camel mounted unit from Bikaner State, the Ganga Risala (Bikaner Camel Corps), was amalgamated with the Jaisalmer Risala raised in 1948 and became the 13th Grenadiers.
The Jodhpur Sirdar Infantry became the 20th battalion of the Rajput Regiment, while the Bikaner Sadul Light Infantry became the 19th battalion.