Prior to Independence, the Indian Civil Service (ICS) was the senior most amongst the Services of the Crown in India.
Besides the ICS, there was also the Indian Police Service.
After Independence, it was felt that though the ICS was a legacy of the imperial period, there was need for the All India Services for maintaining the unity, integrity and stability of the nation.
Accordingly, a provision was made in Article 312 of the Constitution for creation of one or more All India Services common to the Union and State.
The Indian Administrative Service and The Indian Police Service are deemed to be constituted by the Parliament in terms of Article 312 of the Constitution.
After the promulgation of the Constitution, a new All India Service, namely, The Indian Forest Service, was created in 1966.
A common unique feature of the All India Services is that the members of these services are recruited by the Centre, but their services are placed under various State cadres, and they have the liability to serve both under the State and under the Centre.
This aspect of the All India Services strengthens the unitary character of the Indian federation.
Of the three All India Services, namely, the Indian Administrative Service (IAS), the Indian Police Service (IPS), and the Indian Forest Service (IFS), the Ministry of Personnel, Public Grievances and Pensions is the cadre controlling authority for the IAS.
The recruitment to all the three services is made by the UPSC.
These officers are recruited and trained by the Central Government, and then allotted to different State cadres.
There are now 24 State cadres including three Joint cadres, namely,  Assam and Meghalaya,  Manipur and Tripura, and  Arunachal Pradesh, Goa, Mizoram and the Union Territories (AGMUT).
Central Secretariat Services
The Central Secretariat has three services, namely,  Central Secretariat Service (CSS),  Central Secretariat Stenographers’ Service (CSSS) and  the Central Secretariat Clerical Service (CSCS).
The grades of Selection Grade and Grade I of CSS and as well as the Senior Principal Private Secretary and Principal Private Secretary of CSSS are centralised.
Appointments and promotions in the Centralised Grades are made on all secretariat basis by Department of Personnel and Training (DOP&T).