which invading tribe brought about the collapse of the gupta rule
Gupta Empire The empire gradually declined because of many factors such as substantial loss of territory and imperial authority caused by their own erstwhile feudatories, as well as the invasion by the Huna peoples (Kidarites and Alchon Huns) from Central Asia.[11][12] After the collapse of the Gupta Empire in the 6th century, India was again ruled by numerous regional kingdoms. A minor line of the Gupta clan continued to rule Magadha after the disintegration of the empire. These Guptas were ultimately ousted by the Vardhana ruler Harsha, who established his empire in the first half of the 7th century.[citation needed]
Delhi Sultanate Qutb al-Din Aibak, a former Turkic Mamluk slave of Muhammad Ghori, was the first sultan of Delhi, and his Mamluk dynasty conquered large areas of northern India. Afterwards, the Khalji dynasty was also able to conquer most of central India, but both failed to conquer the whole of the Indian subcontinent. The sultanate reached the peak of its geographical reach during the Tughlaq dynasty, occupying most of the Indian subcontinent.[10] This was followed by decline due to Hindu reconquests, states such as the Vijayanagara Empire asserting independence, and new Muslim sultanates such as the Bengal Sultanate breaking off.[11][12]