Harichandra founded the Pratihara kingdom in the middle of the 6th century AD. The Pratiharas were Indian dynasty that ruled a large kingdom in northern India from the 6th to the 11th centuries. However the political history of the Pratiharas was marked with their career of enormous warfare.
The ascendancy of the Pratihara power began with Nagabhatta I, who ascended the throne in the middle of the 8th century. He extended his control in the east and south from Mandor, conquering Malwa as far as Gwalior and the port of Bhrauch in Gujarat. He established his capital at Ujjaini in Malwa. The greatest achievement of Nagabhatta was his victory against the Arabs. The Arabs had snatched a portion of Malwa. Thus the strong foundation of the Pratihara kingdoms was threatened. In this circumstances Nagabhatta inflicted a violent defeat to the Arabs. Thus the defeated Arabs remained confined in the region of Sind and could not penetrate into the heart of India. In due course Nagabhatta united under his banner the Gurjara principalities of Nandipuri and Jodhpur. Nagabhatta installed the strong Pratihara kingdom consisting of Malwa, Gujrat and parts of Rajputana.
In the political history of the Pratiharas, Nagabhatta was succeeded by Vatsaraja. Vatsaraja was the grandnephew of Nagabhatta I. He ruled over as extensive territory comprising central India (Malwa) and Rajputana. While Vatsaraja, was installing his imperial career in western India, the Palas had established a strong monarchy in the east. The Palas were extending their sway over the west. This resulted into the conflict between the Pala and the Pratiharas. At that time the Rashtrakutas were also aspiring for their mastery over the Deccan region. Thus began the famous tripartite struggle, which is very important in the political history of India. The tripartite struggle smashed the very foundation of the Pratihara. Though initially Vatsaraja made enormous victory and annexation through his aggressive policy yet his victory was a short lived one. The Rashtrakuta king Dhruva crushed him as well as the Pratihara kingdom. Vatsaraja was drove away to the deserts of Rajputana in about 783 AD.
However the political history of the Pratiharas was not completely shattered. It revived its lost glory under the rule of Nagabhatta II. He was the son and successor of Vatsaraja. He conquered Sind, Andhra, Vidarbha and Kalinga, which were lost to the Pratiharas. The sweeping success of Nagabhatta made his struggle with the eastern rival, Dharmapala inevitable. Nagabhatta attacked Kanauj and overthrew Chakrayudh, the vassal of Dharmapala there. In the struggle Dharmapala was completely routed in the field of Monghyr. Later he captured the hill forts of Anaratta, Malava, Kirata and Matsya. Thus Nagabhatta II extended the Pratihara kingdom to a vast extent and revived its lost glory. Nagabhatta II`s huge success however was proved a short-lived one. The Rashtrakuta king Govinda III appeared on the north and defeated Nagabhatta in the battle of Bundelkhand.
The reign of Nagabhatta and Vatsaraja constituted an important epoch in the history of ancient India. The political history of the Pratiharas was marked by the achievements of Nagabhatta II and Vatsaraja. They converted a provincial dynasty into a first rate military and political power in ancient India. Although these kings met with crushing defeat under the Rashtrakutas, they laid the foundation of a great kingdom. However the foundation of the great kingdom laid by these early Pratiharas met with considerable success under the Bhoja.
Rambhadra, the son of Nagabhatta II succeeded his father on the Pratihara throne. However the reign of Pratihara king, Rambhadra is shrouded in obscurity. His son Bhoja succeeded Rambhadra. The reign of Bhoja constituted an illustrious period in the history of ancient India. Bhoja I or Mihir Bhoja was beyond all questions a powerful monarch. Soon after his succession Bhoja devoted himself to the task of the consolidation of the Pratihara Empire. The Pratihara Kingdom suffered disruption under the Rashtrakuta invasion. Bhoja re-established the Pratihara supremacy by consolidating the disrupted parts. Consolidating his kingdom, Bhoja started to renew the land grants of his ancestral kingdom. During the period of Rambhadra, those lands had fallen into disuse. Having consolidated his power completely Bhoja turned his attention to the hereditary enemy Palas. He started eastward campaigns and conquered Kanauj, Kalanjar etc. He overran Southern Rajputana and humbled the pride of the Chedis of Tripuri. Bhoja became the Lord of Maddhyadesa.
However Bhoja had to suffer some initial defeats into the hands of the Pala king, Devapala. During his eastward campaigns Devapala defeated Bhoja. Being checked in the east Bhoja set out for his campaign in the south. However he also suffered a defeat in the hands of the Rashtrakuta adversary, Dhruva II in or about 867AD. But Bhoja was a competent ruler and administrator. Bhoja recovered from the initial reverses. He then planned for the renewed schemes of conquests. In the meantime, the death of Devapala opened to Bhoja to avenge his defeat. The Rashtrakutas at that time were also engaged in the struggle with the Chalukyas. In these circumstances, Bhoja made an alliance with the Chedi king and set out for the victorious campaigns. In this course he defeated the Pala king of Bengal. He extended his sway far into the heart of the Pala kingdom. Then he defeated the Rashtrakuta king Krishna II and conquered a part of Malwa and Gujrat. However Bhoja successfully retained his hold over the region of Gujrat and Malwa. Bhoja also made sweeping conquests in the Punjab, Oudh and in other territories in the north. But Sankaravarmana of Kashmir checked his further progress in the north. Thus the kingdom of Bhoja included the whole of northern India, except the part of Kashmir, Sind, the remains of the Pala kingdom of Bihar and Bengal and the Kalachauri kingdom of the Jabbalpore region.
Consolidating his kingdom, Bhoja I established his capital in the imperial city of Kanauj. During his reign the Pratiharas made a dazzling success as the political and military power in India. The reign of Bhoja undoubtedly covers an important eon in the political history of the Pratiharas.
Next to Bhoja, Mahendrapala inherited the Pratihara throne. He was the able son of Bhoja I. The Pala power suffered a decline after the death of Devapala. Taking advantage of this situation Mahendrapala defeated the existing Pala king and extended his sway in the east. He annexed Magadha and a considerable section of northern Bengal. According to some historians, Mahendrapala lost some territories of north to the ruler of Kashmir. From the "Pehoa Inscription" it is known that Karnal district of Punjab continued to be a part of the Pratihara kingdom under Mahendrapala. On a whole the Mahendrapala not only retained the magnificent glory of his father`s kingdom but also made enormous additions to it. The reign of Mahendrapala constituted an important chapter in the political history of the Pratiharas.
Mahendrapala was succeeded by Bhoja II, who ruled for a short period of time and later was succeeded by his brother Mahipala. However the imperial fabric of the Pratiharas began to decline during the reign of Mahipala.
Mahipala started his political career with the successful campaigns against the Mulakas, Mekalas and Kalingas. But the hereditary enmity of the Pratiharas with the Rashtrakutas proved dangerous to the flourishing Empire of the Pratiharas. Indra II, the Rashtrakuta king crushed the Pratihara power under Mahipala and thoroughly sacked the Pratihara capital Kanauj. The "Cambay Inscription" described that Indra III ravaged the Mahodaya or the region of Kanauj and marched upto Prayaga or Allahabad. Mahipala recovered his lost fortune after the withdrawal of Indra to the south. Due to the crushing defeat led by the Rashtrakuta invasion, the Pratihara kingdom was a completely disrupted. The vassal of the Pratiharas already started their struggle for independence. Moreover the newly emerged powers also challenged the supremacy of the Pratiharas. The Rashtrakutas also renewed their invasion against the Pratiharas. Thus the forces of disintegration during the reign of Mahipala weakened the foundation of the Pratihara Empire.