As regards Harshavardhana's reign, we have ample sources of information at our disposal. Dr. V.A. Smith writes, "When all sources are utilized, our knowledge of the events of the reign of Harsha far surpasses in precision that which we possess respecting any other Indian King, except Chandragupta Mauraya and Ashoka." The important sources of information about Harshavardhana and his reign are given below:-
(A) Literary Sources
(I) "Harshacharita" Of Bana
The important source of Harsha's reign is "Harsha charita ". It was written by Banabhatta. He was a writer of great repute in the history of classical Sanskrit, who wrote on Harsha as his court-poet from his personal and intimate knowledge of his life, rule, and has given to Sanskrit, one of its very few biographical works.
Its first chapter is devoted to the life and family of the author himself. The second, third and fourth chapters deal with the ancestors of Harsha and the history of the house of Thaneswar.
The sixth and seventh chapters deal with the wars and conquests of Harsha. The last chapter gives a description of the various religious sects living in the forests of the Yindhyas.
A study of Harshacharita revealed us the idea of the social, religious, economic and political life of the people of India in the time of Harsha. It is true that sometimes Banabhatta has gone to extremes while praising his patron but it cannot be denied that the book gives us a lot of useful information.
Dr. Radhakumud Mookerji has pointed out, "though the historical value of the work as a whole is somewhat vitiated by its occasional outburst of hero-worship and flights of fancy, to which a poet laureate's panegyric on his royal patron naturally tends itself, the time between fact and fiction is easily discernible".
He further writes, "What we thus lack of political history is amply compensated by what we get of social history in the "Harshacharita".
(II) "Si-Yu-Ki" Of Huein-Tsang
Huein-Tsang also known as Yuan-Chwang, the greatest of all the Chinese pilgrims to come to India has left an extremely interesting record of the court of Harsha as well as of the life of the Indian people. Huein-Tsang's "Si-Yu-Ki" is our principal source of information about the Harsha.
He travelled in India from 630 A.D. to 644 A.D. Huein-Tsang gives copious information on the political, religious, educational, material, judicial and moral condition of the people of contemporary India.
In the life of Harsha, Huein- Tsang interposes some interesting facts not fully mentioned by Banabhatta. According to Chinese pilgrim, when the throne of Kanauj on the advice of their leading man Bani invited Harshavardhana, the younger brother of the murdered king to become their sovereign. His account, as Dr. R.K. Mookerji tells us "reads like a Gazetteer in the scope of its enquiry and its wealth of detail".
(III) Harsha's Own Writings
King Harshavardhana is said to have composed three great dramas- "Ratnavali", "Nagananda "and "Priyadarsliika" in Sanskrit language.
The 'Ratnavali' and 'Priyadarshika' deals with love and court intrigues and may rightly be-called "Comedies of Harsha". "Nagananda" is a most useful play. It tells us much about the charity and magnanimity of Harshavardhana.
(B) Epigraphic Sources
Besides the literary sources there are several inscriptions on Harshavardhana's reign, which are given below:-
(I) Sonpat Copper-Seal Inscription
"Sonpat Copper Seal Inscription" helps us in solving the Chronological difficulties about the reign of Harshavardhana such as - about the year 590'A.D. queen Yosovati or Yasomati gave birth to Harsha in the month Jyaistha, on the twelfth day of the dark fortnight.
(D) The Banskhera Plate Inscription
The Banskhera plate inscription of the year 628 A.D. gives us a facsimile of the signature of Harshavardhana which shows that the King Harshavardhana was an expert Calligraphist.
(III) The Madhuban Copper-Plate Inscription
The most important inscriptions on Harsha's reign is the Madhuban Copper Plate Inscription, dated 631 A.D. It traces the genealogy of Harshavardhana upto four generations.
(IV) The Nalanda Seal, the Aioli Inscription of Pulakesin:
These inscriptions help us in getting some useful information on Harsha and his reign.
The coins of Harsha form a reliable source of information of his reign. From the coins, we learn of the important dates, conditions of India, social as well as political.
2. Early Life
Harshavardhana was the second son of Prabakaravardhana, the first important king of Pushyabhuti dynasty with its capital at Thaneswar.
In 606 A.D. Harshavardhana ascended his ancestral throne of Thaneswar, consequent upon the death of his elder brother Rajya-vardhana Harshavardhana was born to the king Prabhakaravardhana and the Queen Yasomati or Yasovati about the year 590 A.D. Harsha had an elder brother named Rajyavardhana and a younger sister Rajyasri. No detailed account of the education of the children is given Harshavardhana anywhere.
Rajyasri was married to Grahavarmana, King of Kanauj. He was the last ruler of Kanauj belonging to the Maukhari royal dynasty.
After the death of Prabhakaravardhana, his eldest son Rajyavardhana became the King of Thaneswar. But the young princes were never at peace and calamity came in battalion.
He received the most shocking news from Samvadaka, the most royal servant of princess Rajyasri that the Malava or Malwa King named Devagupta had invaded Kanauj, murdered Grahavarmana and took away his queen Rajyasri as prisoner to Malava or Malwa.
He instantly led an army with 'Bhandi' as a General for an attack upon Malwa or Malva and instructed his younger brother Harsha to stay at Thaneswar.
However, very soon he was destined to meet a more serious calamity when he received shocking news from Kutala a chief officer of Cavalry, that though the Emperor Rajyavardhana inflicted a crushing defeat upon King Devagupta of Malwa or Malava but he was treacherously killed by the king of Gauda (West Bengal) named 'Sasanka'.
3. Conquests of Harshavardhana
Harshavardhana now succeeded his brother at Thaneswar. His first act was naturally to rescue his sister and avenge the death of his brother and brother-in-law and was quite successful in both.
According to Banabhatta Harshavardhana decided to launch campaigns of "Digvijaya" by "subjugating the four quarters". He sent an ultimatum to all the Kings to either surrender or give battle.
As Harshavardhana was marching against Sasanka, king Bhaskaravarmana of Kamrupa made an overture to him to make common cause against Sasanka. Harshavardhana readily embraced this overture.
As he was advancing, he received the message from his minister Bhandi that Rajyasri had escaped from the prison and was in the forest of Vindhya. Harshavardhana asked Bhandi to command the army against Sasanka and he himself went in search of his sister in Vindhya Mountains.
He came to the rescue of his sister, when she was about to take a plunge in the river to commit suicide. This narration of Banabhatta is an exaggeration, since it was not possible for Rajyasri to go to Vindhya which was very far.
It is highly dramatic for Harshavardhana to arrive at the appropriate moment to save his sister's life. After rescuing Rajyasri, Harshavardhana thought of uniting two kingdoms of Kanauj and Thaneswar because Grahavarmana, the last king of Kanauj and husband of Rajyasri had left no male issue.
Accordingly, in 606 A.D. Kanauj and Thaneswar were united into one kingdom and Harshavardhana became its ruler and assumed family title of "Vardhana." This amalgamation of two states increased the military resources of Harshavardhana.
Harshavardhana's old "Commander-in- Chief, advised him "to end the system which might breed treachery and trouble, the system of petty warring States." As a result he collected a huge force of 5000 elephants, 20,000 cavalry and 50,000 infantry and set out on his career of conquest.
(I) Conquest of Bengal
First, he decided to avenge the death of his brother which has taken place at the hands of Sasank, king of Bengal. Therefore, he sent a big expedition probably under his general Bhandi against Sasank. The details of war are not known. Sasank was probably defeated. But the victory of Harshavardhana was not decisive.
Later on, Harshavardhana made an alliance with king Bhaskaravarman of Kamrupa, to make joint war against Sasank. Though, this alliance was that Sasank defeated but was not completely crushed.
After this defeat, Sasank began to negotiate with Pulakesin-II, the Chalukya king of Deccan, against Harshavardhana. Thus, the Bengal ruler continued to be a source of trouble for Harshavardhana throughout his reign till the death of Sasartka.
(II) Conquest of the Five Indies
According to Huein-Tsang, Harshavardhana spent five years and a half of his reign in conquering the "Five Indies". From 606 to 612 A.D. he conquered the five states in Northern India viz, 'Svarasta'or 'Punjab', "Kanyakubja" or 'Kannauj', 'Gonda' or 'Bengal', 'Mithua' or 'Bihar' and 'Utkala' or 'modern Orissa' or in the words of Huein Tsang "he went from East to West, subduing all who were not obedient, the elephants were not harnessed, nor the soldiers un helmeted."
(I) Conquest of Valabhi or Gujarat
Prabhakaravardhana, the father of Harshavardhana had faced a host of enemies consisting of "Lata" or Gujarat, "Malava" or Malwa and Gujaras. Harshavardhana had to face the legacy of their hostility. The kingdom of Valabhi in Gujarat was a formidable power. It appears that there was a war between Harshavardhana and the king of Valabhi.
We do not have any detail of events of that war. Although in first encounter Harshavardhana mauled the king of Valabhi but the situation was saved on account of the help given to the king Valabhi by Dadda-II, Gurjara king of Broach recovered his position. Perhaps Dhruvasena-I or Dhruvabhatta.
The hostilities ended in the marriage of Harshavardhana's daughter with Dhruvasena II or Dhruvabhatta. After that Valabhi became a subordinate ally of Harshavardhana.
(II) War with Pulakesin-H
Pulakesin-II the Vatapi, had design to become the lord paramount of the South. The old enemies of Thaneswar-"Lata" or Gujarat, "Malavas" or Malwa and "Gurjaras" made common cause with Pulakesin-II and became his feudatories. This resulted in Harshavardhana's war with Pulakesin- II.
According to Huein Tsang Harshavardhana, in order to smash Pulakesin, raised a vast army from the five Indies and personally conducted the campaign against Pulakesin-H. However, he was unable to defeat Pulakesin-D.
It was claimed that Pulakesin-H acquired the title of "Parmeshwar" "by defeating Harshavardhana, the warlike lord of all the regions of the North." The poet Ravikirti in the Aihole inscription of 634 A.D. indicates that the battle was fought somewhere between the Vindhya and the "Reva" or "Narmada".
There are many other inscriptions in which Pulakesin-H is described as defeating Shri Harsha, the Lord of the whole Northern India. The view of Dr. V. A. Smith was that Pulakesin-H "guarded the passes on the Narmada so effectively that Harshavardhana was constrained to retire discomfited and to accept that river as his frontier.
(v) Campaigns of Send, Nepal and Kashmir
Banabhatta refers to that Harshavardhana had also said to have subdued Sind and a land of snowy mountains probably Nepal and Kashmir. But historians doubt the accuracy of this statement. But it is well-known that Sind was hostile to Prabhakar Varmana and it is possible that Harshavardhana might have led a campaign against it.
However the account of Huein-Tsang shows that Sind was a strong and independent kingdom when he visited it. This proves that Harshavardhana was not successful against the Sind. Probably the states of Nepal and Kashmir were outside the empire of Harshavardhana.
Harshavardhana made an alliance with Baskaravarmana, the ruler of Kamrupa. This was done to create a second front against Sasank, the powerful enemy of Harshavardhana.
But in this alliance an equal position was not conceded to Bhaskaravarmana, as it revealed from the fact that the Raja of Kamrupa was present in Harshavardhan's "Kanauj Assembly" with 20,000 elephants and presents.
Thus, it seems that Harshavardhana not only made an alliance with the ruler of Kamrupa but also made him to acknowledge his suzerainty. Probably, Bhaskaravarmana got possession of this territory after the death of Harshavardhana.
(vii) Conquest of Ganjam
The modern Ganjam district was a small independent State in the seventh century. It was then known as Kongoda. Harshavardhana had tried several times to conquer it but for some reason or other failed to annex it.
In 643 A.D. Harshavardhana led a huge expedition and conquered Ganjam. This was his last conquest. After its conquest, a Mahayana Conference was held in Orissa and Buddhist scholars from Nalanda were invited to it. It was after the Conference that Harshavardhana offered to Jayasena, the Buddhist scholar, the revenue of eighty large towns of Orissa."
(viii) Relations with Asiatic Powers
Harshavardhana also maintained very cordial relations with the great Asiatic powers like Persia and China. From Tara Nath's account we find the Harsha exchanged gifts with Persian emperor. In 641 A.D. Harshavardhana sent a "Brahmana" envoy to the court of Chinese emperor.
In 643 A.D., a Chinese mission came along with reply Ma-Twanlin gives the detailed description, "Siladitya assumed the title of king of Magadha and sent an ambassador with a letter to the emperor.
The emperor, in his, sent 'Liang- lioai-king' as an envoy with a royal patent of Siladitya with an invitation to him to submit, Siladitya was full of astonishment and asked his officers whether any Chinese envoy ever came to this country since time immemorial, "Never, they replied in one voice.
There upon the king went out, received the imperial decree with bending Knees, and placed it on his head". In 643 A.D. a second Chinese mission came to India under 'Li-y-Piao' and Wang-Huein-tse. This mission brought the reply of the Chinese emperor and its members were received with great respect and honour. Wang-Huein-tse was sent back to India immediately after his arrival in China.
This mission was probably sent after the receipt of the letter which Harshavardhana had sent through Huein-Tsang. Wang-Huein-tse left for India in 646 A.D. along with Tsiang-Cheujenn. Unfortunately, Harshavardhana was dead before the arrival of the third Chinese mission. In this way, these missions reveal that Harshavardhana also had diplomatic relations with China.
(ix) Extent of Harsha's Empire
Harshavardhana had a vast empire. It stretched from the Brahmaputra delta in East to Kathiawar in the West and North -Western Punjab in North-West to the Narmada River in the South which included the Eastern Punjab, Malava or Malwa, Kanauj, Bihar, Bengal and Orissa.
Sind, Nepal and Kashmir (according to Banabhatta) were the Controversial territories because no other contemporary or near-contemporary chroniclers have indicated that these territories were the part of Harshavardhana's kingdom. Hence these were shown as the controversial territories in the map (See Map 12:1).
Thus in brief, Harshavardhana was the master of the whole of the Northern India except its Northwestern regions. He changed his capital from Thaneswar to Kanauj. This he had to do because his Empire included a greater portion of Eastern India, which could not be easily governed from Thaneswar.