After the reign of King Harshavardhana, began a prolonged period of political decentralization between the 8th and 10th centuries during which several kingdoms struggled for supremacy. In Northern India, the three major kingdoms were those of the Palas, the Pratiharas and the Rashtrakutas. Smaller kingdoms or principalities were established by the Rajput Dynasties of the Chauhans, Paramaras, Gahadavalas.
In the South, it was the Chola Dynasty that had control over most of the peninsular part of the country. This situation of fragmentation of political authority was greatly favourable for an invader like Mahmud of Ghazni. After several successful conquests in Western and Central Asia, Mahmud turned toward India. His Indian conquests began in 1000 AD, after which he made repeated invasions over Punjab, as far as Kashmir and Eastern Rajasthan and then into the fertile area of the Gangetic Plains. However, Mahmud was not interested in establishing his rule over this country.
Mahumud’s invasions were followed by the coming of the Turks. The Turks established their rule over most of Northern India by the 13th century. The Turkish rulers were known as Sultans and ruled from their capital at Delhi. Their Empire is thus called the Delhi Sultanate. Its most powerful dynasties were those of the Khaljis and the Tughluqs. Most of these rulers had to face the threat of invasions by the Mongols.
Meanwhile in the South, the two powerful kingdoms of Vijayanagar and Bahmani were constantly competing with each other for political supremacy. The coming of the Mughals in early 16th century marked a new era in Indian History. Politically, it saw the consolidation of an all India Empire on a scale that had not been witnessed in India for a long time. Socially and culturally, this was a period of fusion of various traditions. Out of this fusion was born a unique tradition which could be seen in the social life, religious practices and beliefs, and in the various arts. It was based on mutual acceptance and a harmonious coexistence.
Parallel to these centralized empires such as the Delhi Sultanate and the Mughal Empire, there flourished several smaller regional and provincial independent ruling dynasties. Some of these were the Ilyas Shahi and Husain Shahi Dynasties of Bengal, the Ahoms of Assam, the Gajapati Dynasty of Odisha, the Dynasties of Mewar and Marwar in Rajasthan and the Sharqi Dynasty of Jaunpur. The reign of these independent regional dynasties witnessed the growth of strong and flourishing regional and sub-regional languages, literature and cultures.
The Delhi Sultanate was a Delhi-based Muslim kingdom that stretched over large parts of India for 320 years (1206-1526). Five dynasties ruled over Delhi Sultanate sequentially, the first four of which were of Turkic origin and the last was the Afghan Lodi. The Lodi dynasty was replaced by the Mughal dynasty.
The five dynasties were:
Delhi first became the capital of a kingdom under the Tomara Rajputs, who were defeated in the middle of the twelfth century by the Chauhans of Ajmer. It was under the Tomaras and Chauhans that Delhi became an important commercial centre. The transformation of Delhi into a capital that controlled vast areas of the subcontinent started with the foundation of the Delhi Sultanate in the beginning of the thirteenth century.
Qutb-ud-din Aibak, a former slave of Muhammad Ghori, was the first sultan of Delhi and his dynasty conquered large areas of northern India. Afterwards the Khilji dynasty was also able to conquer most of central India, but both failed to unite the Indian subcontinent.
Delhi Sultanate reached its peak in terms of geographical reach, during the Tughlaq dynasty, covering most of Indian subcontinent. The Delhi Sultanate declined thereafter, with continuing Hindu-Muslim wars, and kingdoms such as Vijayanagara Empire re-asserting their independence as well as new Muslim sultanates such as Bengal Sultanate breaking off.
In 1526, the Delhi Sultanate fell and was replaced by the Mughal Empire.