Introduction:
The Turks, Afghans, and Mongols played significant roles in shaping the history of India. Each of these groups entered India through different circumstances and left lasting impacts on the region. Let's explore how they entered India and the consequences of their arrival.

1. Turks:
The Turks initially invaded India in the 11th century under the leadership of Mahmud of Ghazni. He launched numerous expeditions into northern India, primarily targeting Hindu temples and kingdoms to plunder their wealth. These raids established a pattern of Turkic incursions into the Indian subcontinent. However, it was with the arrival of Muhammad Ghori, a Turkic ruler, in the late 12th century that the Turks gained a firm foothold in India. Ghori defeated Prithviraj Chauhan, the ruler of Delhi, in the Battle of Tarain in 1192 and established the Delhi Sultanate, marking the beginning of Turkic dominance in northern India.

2. Afghans:
The Afghan invasion of India occurred during the late medieval period. The Delhi Sultanate, weakened by internal conflicts, faced invasions from various Afghan rulers. The most notable Afghan invader was Sher Shah Suri, who overthrew the last ruler of the Delhi Sultanate and established the Sur Empire in 1540. The Afghan influence in India reached its peak under the reign of Sher Shah, who introduced administrative reforms and constructed the Grand Trunk Road. However, the Mughals, led by Babur, an Uzbek Turkic prince, ultimately defeated the Afghans and established the Mughal Empire in India.

3. Mongols:
The Mongol invasion of India occurred during the reign of the Delhi Sultanate. The Mongols, led by Timur (Tamerlane), invaded India in 1398. Timur launched a series of devastating raids, resulting in the sack of Delhi and the massacre of its inhabitants. However, the Mongol incursion had limited long-term impact on India, as Timur did not establish a lasting Mongol presence in the region. The Delhi Sultanate managed to recover from the Mongol invasion, albeit weakened.

Consequences:
- The arrival of the Turks, Afghans, and Mongols in India led to significant cultural and religious changes. The Turks brought Islam to India, which later became a prominent religion in the region.
- The Turkic and Afghan invasions also resulted in the establishment of various dynasties, such as the Delhi Sultanate and the Mughal Empire, which played crucial roles in shaping Indian history.
- The Turkic and Afghan rulers introduced new architectural styles, such as the Indo-Islamic architecture, which blended Persian and Indian elements.
- These invasions also led to the decline of Hindu kingdoms and the subjugation of indigenous rulers.
- The Turkic and Afghan rulers implemented new administrative systems and introduced Persian as the court language, influencing the cultural and linguistic landscape of India.

In conclusion, the Turks, Afghans, and Mongols entered India through military campaigns and conquests. Their invasions resulted in significant political, cultural, and religious changes, leaving lasting imprints on Indian history.