After adopting these measures Nadir marched to Ispahan. He first upbraided Shah Tamasp, and then pretended to be reconciled to him; but the scene of his mock submission to this Prince drew to a close. Tamasp was invited to the tents of his general to share in the joys of a feast, which terminated in his being seized and dethroned. He was sent to Khorasan. The Mahometan author who records these events is careful in informing us that the generosity of Nadir desired that Tamasp, though a prisoner, should be accompanied by all his ladies, and enjoy every other comfort that could be deemed necessary to pleasurable existence.

The time did not yet appear to Nadir to be ripe for his seizing the crown of Persia. The officers of his army and some venal nobles of the court earnestly requested that he, who was alone worthy to wear the diadem, would place it upon his head; but he rejected their entreaties, from pretended respect for the blood of the Suffavean kings. The son of Tamasp, an infant only eight months old, was seated upon the throne, and Nadir accepted the name and power of regent of the empire.

When the ceremonies necessary at this coronation were over, Nadir marched with a large army to the attack of Bagdad. The Governor of that city, Achmet Pacha, was not more distinguished for his talents as a soldier than a statesman; and the Persian leader had made his preparations in the expectation of an obstinate defence; but neither the valor nor skill of Achmet would have saved his city had not the Turkish general Topal Osman advanced, at the head of an immense army, to his relief. Nadir instantly resolved to hazard a battle. He left a small part of his army in his lines, and led the remainder to attack Topal Osman, who was encamped on the banks of the Tigris, near the village of Samarra, which is situated about sixty miles from Bagdad. The action that ensued was one of the most bloody ever fought between the Turks and Persians. It was at first favorable to the latter, whose cavalry put the enemy to flight; but the Turkish infantry advanced and restored the battle. A corps of Arabs, from whom Nadir expected support, fell upon one of his flanks. His men, who had been exposed all day to the intense rays of a summer sun, fainted with heat and thirst. He himself twice fell to the ground, in the midst of his enemies, from his horses being shot; and his standard-bearer, conceiving him slain, fled from the field. All these causes combined to give the victory to Topal Osman; and, after a contest of more than eight hours, the army of Nadir was completely defeated. The moment the news of this event reached Bagdad, the inhabitants of that city fell on the troops left to guard the trenches, who were also routed. The loss of the Persians in this battle was estimated by their enemies at sixty thousand men; and it probably amounted to more than one-third of that number. The Turks suffered almost as severely; but their triumph was very complete; for Nadir did not reassemble the whole of his broken and dispersed army till he reached the plains of Hamadan, a distance of more than two hundred miles from the field of action.

There is no period in the life of Nadir at which he appears to more advantage than after this great misfortune. Instead of reproaching his soldiers with their defeat, he loaded them with praises and with favors. Their losses in money and horses were more than repaid, and they were encouraged by the exhortations as well as the actions of their politic commander to desire nothing so much as an opportunity of revenging themselves upon their enemies. This conduct increased his reputation and popularity to so great a degree that recruits from every part of Persia hastened to join his standard; and in less than three months after this action Nadir descended again into the plains of Bagdad with an army more numerous than before.

His brave antagonist, Topal Osman, had jealous rivals at the court of Constantinople; and these, alarmed at the great fame he had acquired, not only prevented, by their intrigues, his being reënforced with men, but, by withholding the supplies of money that were necessary to pay his troops, compelled him to separate his force. He, nevertheless, made the greatest efforts to oppose this second invasion of Nadir. He sent a corps of cavalry to arrest the progress of the Persians; but the latter, eager for revenge, made such a sudden and furious attack on this body that they completely routed it. On hearing this intelligence, the Turkish general advanced with all the troops he had been able to draw together to his support; but his own army partook of the panic of their flying comrades. Topal Osman endeavored in vain to rally them. He was himself so infirm that he always rode in a litter. His attendants, in the hope that he might escape, lifted him, when the flight became general, upon a horse; but his rich dress attracted the eye of a Persian soldier, who pierced him with his lance, and then, separating his head from his body, carried it to his commander. We are pleased to find that Nadir respected the remains of his former conqueror. His head and corpse were sent by an officer of rank to the Turkish army, that they might receive those honorable rites of sepulture which in all nations are considered due to a great and valiant soldier.

After the death of Topal Osman and the defeat of his army Nadir proceeded to invest Bagdad; but being alarmed at the account of a serious revolt in the province of Fars, he readily listened to the terms which the ruler of the city proposed, which were that the governments of Turkey and Persia should repossess the countries that belonged to them in the reign of Sultan Hasan before the Afghan invasion. The rebellion which had compelled him to retire from the Turkish territories had hardly been suppressed before he learned that the Emperor of Constantinople had refused to ratify the engagements made by the Pacha of Bagdad, and had sent a general, named Abdallah, at the head of a large force, with orders either to conclude peace or to continue the war, as circumstances should render it expedient. Nadir hastened to occupy Armenia and Georgia, which were the principal of the disputed provinces. He threw a bridge over the rapid Araxes; and at once invested the cities of Tiflis, Gunjah, and Erivan, in the hope that the danger with which they were threatened would lead the Turkish general to hazard an action. Nor was he deceived.

Abdallah, encouraged by his superior numbers, left the intrenchments with which he had covered his army, and attacked the Persians on the plains of Baghavund, near Erivan. The Persian leader, when he saw him advancing, addressed his troops in the most animated language. "Their enemies," he said, "outnumbered them eight to one; but that was only an incitement to glorious exertion. He had dreamt on the past night," he told them, "that a furious animal had rushed into his tent, which, after a long struggle, he had slain. With such an omen," he exclaimed, "success is certain to those who fight under the protection of his great arm, who raiseth the weak to glory, and casteth down the proudest oppressors." If his troops were encouraged by this speech, they were still more so by his example. After his skill had made the most able disposition of his army, he rushed upon the enemy at the head of his bravest men; and wherever he led, the Persians were irresistible. In one of these charges Abdallah Pacha was slain by a soldier, who brought his head to Nadir; and as the battle still raged, he directed it to be fixed upon a spear and to be displayed where it would be best seen by the enemy. The effect was as he anticipated. The Turks, perceiving their general was slain, fled in every direction and left the plain covered with their dead. This victory was followed by the submission of the cities of Gunjah and Tiflis; and those of Kars and Erivan, with all the former possessions of the Persians in that quarter, were soon afterward ceded to him by the policy of the Ottoman court, who, taught by misfortune, were glad to conclude a peace on the basis which had been before settled by the Pacha of Bagdad.

The period was now arrived when Nadir thought he might lay aside the veil which he had hitherto used. An account was brought that the infant sovereign of Persia had died at Ispahan, and consequently that the throne was vacant. It has always been the usage of the kings of Persia to observe the Nuroze, or vernal equinox, as a great festival; and on it all the chief officers, civil and military, of the government appear at court. Nadir issued an order that not only these, but every person of rank and consideration in the kingdom, should meet him on the day of that festival, on the plains of Chowal Mogam, where he ordered a number of temporary buildings to be erected and made every preparation to receive them with splendor and magnificence. We are informed that upward of one hundred thousand persons attended this celebrated meeting; and if this includes the troops, the amount is probably not exaggerated.

Nadir, his historian informs us, assembled the principal nobles and officers on the morning of the festival, and addressed them in the following terms: "Shah Tamasp and Shah Abbas were your kings, and the princes of their blood are the heirs to the throne. Choose one of them for your sovereign, or some other person whom you know to be great and virtuous. It is enough for me that I have restored the throne to its glory and delivered my country from the Afghans, the Turks, and the Russians." He retired, that their deliberations might seem more free, but was soon recalled to hear their unanimous request that he who had saved his country and was alone able to protect it, would accept the crown. He refused this offer, protesting solemnly that the idea of ascending the throne of Persia had never once entered his imagination! The same scene was enacted every day for a month, till Nadir, appearing to be subdued by their earnest solicitations, agreed to comply with their wishes, but said, when he made this apparent concession: "I must insist that, as I sacrifice so much for Persia, the inhabitants of that nation shall, in consideration for one who has no object but their tranquillity, abandon that belief which was introduced by Shah Ismail, the founder of the Suffavean dynasty, and once more acknowledge the legitimate authority of the four first caliphs. Since the schism of Shiah has prevailed," he added, "this country has been in continued distraction; let us all become Sunnis, and that will cease. But as every national religion should have a head, let the holy imam Jaffer, who is of the family of the Prophet, and whom we all venerate, be the head of ours." After the assembly had consented to this change, and a royal mandate had been issued to proclaim it, Nadir informed them that he would communicate what had been done to the Emperor of Constantinople, and require that monarch to give full effect to this advance to general concord among Mahometans; and he would also insist that, as there were now four orthodox sects among Sunnis, the Persians, under the name of the sect of Jaffer, should be admitted as the fifth, and that another column should be added to the four which already decorated the temple at Mecca, in honor of this new branch of the true religion.

The historian of Nadir is careful in informing us that the crown of Persia was placed upon the head of the conqueror exactly at twenty minutes past eight on the morning of February 26, 1736. The moment, no doubt, had been fixed by the most skilful astrologers. The ceremony was performed in a splendid hall erected for the occasion, and Nadir was seated on a throne covered with precious jewels. Various coins were immediately struck in his name, on which was the following inscription: "The impression stamped on this gold proclaims to the world the sovereignty of Nadir, native of the land of Persia, and the monarch who subdues the earth." On the reverse was a short Arabic sentence, which signified "That which has happened is the best." But even the flatterer who records these particulars confesses that there were malicious wits who made free with the latter sentence, and, by the alteration of the position of one letter, made it signify "That which has happened is not the best."