During the medieval times, the state was governed by King Harshavardana. After his death the rule of Partiharas became prominent in Haryana and they continued to rule. The state of haryana also came under the rule of Prithvi Raj Chauhan and it is evident from the forts of Prithviraj Chauhan at Hansi and tarori. The state was invaded during medieval times by Muslim rules like Muhammad Ghori. Much of the states ancient infrastructure is owed to the efforts of Firoz Shah Tughlaq who ruled Haryana also.

The state is a witness of all the three battles of Panipat and every battle shaped Indian history substantially. These battles allowed Mughal emperors to establish themselves in India.

The British colonizers made their way into the state through the second Anglo-Sikh war. The war brought almost the whole of Haryana under the British rule and the rest of the part was under the governance of princely states.

The state of Haryana was formed by the recommendation of Sardar Hukum Singh committee on 1st November 1966.