Some of the causes of the downfall of the Maurya Empire are as follows:
No political empire lasts forever. Whether Persian, Indian, or Roman, every empire in history broke down for certain obvious causes.
Among these causes, some causes appear almost as common, namely, the weak successors, vastness of the empire, independence of the provinces, foreign invasion, and internal revolt. The Maurya Empire fell because of these causes.
1. Weak Successors of Asoka:
The first three Maurya Emperors were men of exceptional abilities. As heroes, conquerors, and administrators, they were indeed great. But, heredity in succession does not guarantee ability in character for all time or all successors to follow. Asoka’s sons and grandsons did not prove themselves worthy of the Great Mauryas.
Asoka’s sceptre, it is said, was like the bow of Ulysses which could not be drawn by weaker hands. It is also said that he was succeeded by a progeny of pygmies whose “shoulders were not fit to bear the weight of his mighty monarchy.” As long that great Emperor ruled, the empire having risen from glory to glory, maintained its vitality to its best. But no sooner he closed his eyes, his weak successors showed no ability to preserve the fabric of the empire.
The weakness of the later Mauryas is established by the fact that the Puranic and other literary sources do not show agreement regarding the order of succession or the names of Asoka’s successors. Different sources, Hindu, Buddhist and Jaina, give confusing accounts of these rulers. While the Vayu Purana says that Kunala ruled for eight years, the Jaina and Buddhist sources say that it was Samprati, the son of Kunala, who succeeded to the throne immediately after Asoka. If Asoka’s son Kunala was blind, he was clearly incapable of ruling, and that might have created a difficult situation. Monarchy always suffered from dynastic tragedy whenever a weak or invalid son stood on the line of succession.
If Asoka’s another son Jalauka ruled over Kashmir, as described in the Kashmir Chronicle, it clearly indicates that no single son of Asoka was capable of ruling over the entire Maurya Empire. That proves the weakness of the later Mauryas. It is not known what happened to Asoka’s another son by Queen Karuvaki, Tivara, and if he was strong or weak to succeed to the Maurya throne.
Much less is known about Asoka’s grandsons except confusing accounts of their existence. The names of several Maurya princes are mentioned in various literary sources. One of these princes was Dasaratha who left three inscriptions on the Nagarjuni hills near Gaya, inscribing his gift of three rock-cut caves to the Ajivika monks. It is evident that the empire disintegrated soon after Asoka’s death without having a strong monarch to keep it together.
2. Vastness of the Empire:
The Maurya Empire was too vast in its extent. While extending to the farthest corners of the Indian sub-continent it also included territories outside the natural frontiers of India. This vastness was itself a source of weakness rather than of strength because of the lack of communication. Distances were so great that the empire could not remain a closely integrated political unit for a longer time.
No doubt, there was an elaborate system of administration as left by Chandragupta and Asoka. But the whole machinery worked under the direction of the centre. The highly centralized character of the government suffered from a grave defect. It depended on the king for all major policies. As the king was the pivot of the whole machinery, the success of the administration depended on his personality.
If the king was strong, the centre was strong. If he was weak, the centre became weak. Once the centre became weak, the administration of the distant provinces also became weak. In the days of the later Mauryas this is what exactly happened. The weak centre under a weak king could not govern the vast empire. As a result, the Maurya administration collapsed and the empire began to disintegrate.
3. Independence of the Provinces:
Though the Maurya administration from the days of Chandragupta was strong enough to control the distant provinces bound to a centralised system, it was also necessary for the provincial governments to enjoy sufficient power. When the centre declined and its authority became weak, the provinces assumed independent character.
It is evident that soon after Asoka’s death, the various Maurya provinces broke away from the centre. The personality as well as the greatness of that monarch was the real cohesive force for imperial unity. As no single son of Asoka was capable of ruling the united empire, the first sign of disintegration was seen with their divided rule.
Kalhana, the author of the famous Kashmir Chronicle Rajatarangini writes that Asoka’s son, Jalauka, ruled over Kashmir as an independent king after his father’s death. More than that, he conquered some other places like Kannauj for his kingdom. This shows how the distant provinces of the empire rose as independent kingdoms.
There is no doubt that soon after Asoka’s death his conquered country of Kalinga became independent. From the Tibetan sources it is known that Virasena ruled independently in Gandhara. From later literary sources it is gathered that Vidarbha became independent of Magadha. From the Greek sources it is known that in the north-western frontiers of the Maurya Empire a king named Subhagasena (Sophagasanus) began to rule independently.
He was described by Polybius, the Greek writer, as the ‘King of the Indians.’ This king faced an invasion of King Antiochus III of Syria, but was powerful enough to force the invader of ‘friendship with him’. This happened about 206 B.C., not long after Asoka’s death. Subhagasena ruled over the northern provinces of the former empire. These evidences prove that the Maurya Empire disintegrated when its provinces became independent under powerful or semi powerful rulers.
4. Foreign Invasion:
From the days of Alexander’s invasion, the north-west frontier of India remained exposed to the Greeks. Chandragupta Maurya drove out the Greeks from the Indian soil, and by defeating Seleukos Nikator established his authority outside the Indian frontiers. During the rule of Bindusara and Asoka, there was no fear from the Greek powers as they were fearful of the Maurya army.
But, after Asoka’s death when the Maurya Empire declined and disintegrated, the Greeks once again cast their greedy eyes on India. The Greek writer Polybius refers to the unsuccessful attempts of King Antiochus the Great to conquer the Indian lands. He had crossed the Hindu Kush and had descended on Indian territories.
After, that, references are available to further Greek invasions. From a later work. Gargi Samhita, it is known that the Greeks entered deep into Indian territories as far as Mathura and Oudh. These might have been plundering raids, but the entry of the foreigners towards the interior areas of the Maurya Empire proved that the empire was no longer capable of defending itself.
5. Internal Revolt:
When the Maurya rule was thus weakening and the empire was breaking up within the half century after Asoka’s death, there finally came a death blow to it by an internal revolt. This revolt was led by the chief of the Maurya army, General Pushyamitra in about 185 or 186 B.C. when the Maurya King Brihadratha ruled in Magadha.
It was a military coup d’etal. General Pushyamitra was a Brahmin, though in army profession. The Puranas state that “Pushpamitra (Pushyamitra) the Senapati will rule the kingdom by assassinating his own master.” Bana, the famous author of Harsha-Charita describes the incident saying that Pushyamitra held a parade of the army to which he invited the King to witness, and thus created an occasion to kill him on the spot with the support of the army.
Thus ended the dynasty of the Mauryas. The fall of the Maurya Empire was a tragedy no doubt. The first great Indian empire which gave to the country a glorious period, vanished forever. But “the moral ascendancy of Indian culture over a large part of the civilised world, which Asoka was mainly instrumental in bringing about, remained for centuries as a monument to her (India’s) glory and has not altogether vanished even now after the lapse of more than two thousand years.”