Beginning of the decline of the Mughal Empire can be traced to the strong rule of Aurangzeb.
Aurangzeb inherited a large empire, yet he adopted a policy of extending it further to the farthest geographical limits in the south at the great expense of men and materials.
In reality, the existing means of communication and the economic and political structure of the country made it difficult to establish a stable centralized administration over all parts of the country.
Aurangzeb’s objective of unifying the entire country under one central political authority was, though justifiable in theory, not easy in practice.
Aurangzeb’s futile but arduous campaign against the Marathas extended over many years; it drained the resources of his Empire and ruined the trade and industry of the Deccan.
Aurangzeb’s absence from the north for over 25 years and his failure to subdue the Marathas led to deterioration in administration; this undermined the prestige of the Empire and its army.
In the 18th century, Maratha’s expansion in the north weakened central authority still further.
Alliance with the Rajput rajas with the consequent military support was one of the main pillars of Mughal strength in the past, but Aurangzeb's conflict with some of the Rajput states also had serious consequences.
Aurangzeb himself had in the beginning adhered to the Rajput alliance by raising Jaswant Singh of Kamer and Jai Singh of Amber to the highest of ranks. But his short-sighted attempt later to reduce the strength of the Rajput rajas and extend the imperial sway over their lands led to the withdrawal of their loyalty from the Mughal throne.
The strength of Aurangzeb’s administration was challenged at its very nerve center around Delhi by Satnam, the Jat, and the Sikh uprisings. All of them were to a considerable extent the result of the oppression of the Mughal revenue officials over the peasantry.
They showed that the peasantry was deeply dissatisfied with feudal oppression by Zamindars, nobles, and the state.
Aurangzeb's religious orthodoxy and his policy towards the Hindu rulers seriously damaged the stability of the Mughal Empire.
The Mughal state in the days of Akbar, Jahangir, and Shahjahan was basically a secular state. Its stability was essentially founded on the policy of noninterference with the religious beliefs and customs of the people, fostering of friendly relations between Hindus and Muslims.
Aurangzeb made an attempt to reverse the secular policy by imposing the jizyah (tax imposed on non-Muslim people), destroying many of the Hindu temples in the north, and putting certain restrictions on the Hindus.
The jizyah was abolished within a few years of Aurangzeb’s death. Amicable relations with the Rajput and other Hindu nobles and chiefs were soon restored.
Both the Hindu and the Muslim nobles, zamindars, and chiefs ruthlessly oppressed and exploited the common people irrespective of their religion.
Aurangzeb left the Empire with many problems unsolved, the situation was further worsened by the ruinous wars of succession, which followed his death.
In the absence of any fixed rule of succession, the Mughal dynasty was always plagued after the death of a king by a civil war between the princes.
The wars of succession became extremely fierce and destructive during the 18th century and resulted in great loss of life and property. Thousands of trained soldiers and hundreds of capable military commanders and efficient and tried officials were killed. Moreover, these civil wars loosened the administrative fabric of the Empire.
Aurangzeb was neither weak nor degenerate. He possessed great ability and capacity for work. He was free of vices common among kings and lived a simple and austere life.
Aurangzeb undermined the great empire of his forefathers not because he lacked character or ability but because he lacked political, social, and economic insight. It was not his personality, but his policies that were out of joint.
The weakness of the king could have been successfully overcome and covered up by an alert, efficient, and loyal nobility. But the character of the nobility had also deteriorated. Many nobles lived extravagantly and beyond their means. Many of them became ease-loving and fond of excessive luxury.
Many of the emperors neglected even the art of fighting.
Earlier, many able persons from the lower classes had been able to rise to the ranks of nobility, thus infusing fresh blood into it. Later, the existing families of nobles began to monopolies all offices, barring the way to fresh comers.
Not all the nobles, however, bad become weak and inefficient. A large number of energetic and able officials and brave and brilliant military commanders came into prominence during the 18th century, but most of them did not benefit the Empire because they used their talents to promote their own interests and to fight each other rather than to serve the state and society.
The major weakness of the Mughal nobility during the 18th century lay, not in the decline in the average ability of the nobles or their moral decay, but in their selfishness and lack of devotion to the state and this, in turn, gave birth to corruption in administration and mutual bickering.
In order to increase emperors’ power, prestige, and income, the nobles formed groups and factions against each other and even against the king. In their struggle for power, they took recourse to force, fraud, and treachery.
The mutual quarrels exhausted the Empire, affected its cohesion, led to its dismemberment, and, in the end, made it an easy prey to foreign conquerors.
A basic cause of the downfall of the Mughal Empire was that it could no longer satisfy the minimum needs of its population.
The condition of the Indian peasant gradually worsened during the 17th and 18th centuries. Nobles made heavy demands on the peasants and cruelly oppressed them, often in violation of official regulations.
Many ruined peasants formed roving bands of robbers and adventurers, often under the leadership of the zamindars, and thus undermined law and order and the efficiency of the Mughal administration.
During the 18th century, the Mughal army lacked discipline and fighting morale. Lack of finance made it difficult to maintain a large number of army. Its soldiers and officers were not paid for many months, and, since they were mere mercenaries, they were constantly disaffected and often verged on a mutiny.
The civil wars resulted in the death of many brilliant commanders and brave and experienced solders. Thus, the army, the ultimate sanction of an empire, and the pride of the Great Mughals, was so weakened that it could no longer curb the ambitious chiefs and nobles or defend the Empire from foreign aggression.
A series of foreign invasions affected Mughal Empire very badly. Attacks by Nadir Shah and Ahmad Shah Abdali, which were themselves the consequences of the weakness of the Empire, drained the Empire of its wealth, ruined its trade and industry in the North, and almost destroyed its military power.
The emergence of the British challenge took away the last hope of the revival of the crisis-ridden Empire.