Persia, at this time, was under the rule of Shah Ismail, a most capable and successful ruler, who had renovated the kingdom, and added largely to it by the conquest and subjection of many minor adjoining States. The two potentates were well matched in vigour and ability. When war with Persia was propounded by Selim in his council, there was ominous silence. There was evidently fear of the undertaking. The Janissary guarding the entrance to the chamber broke down the suspense by throwing himself on his knees before Selim and expressing ardent support to the war. This precipitated a decision by the council, and the Janissary was at once promoted to high office.
Early in March, 1514, a hundred and forty thousand men and three hundred guns were collected on the Asian side of the Bosphorus, under command of the Sultan. Sixty thousand camels were provided to carry its baggage and munitions. The army commenced its march on April 20th. Its aim was Tabriz, then the capital of Persia, distant from Scutari, as the crow flies, by over one thousand miles of a mountainous country, in which there were no roads. The main difficulty was the supply of the army with food for men, horses, and camels. This was partly effected from Trebizond, to which the command of the Black Sea enabled Selim to send supplies from Constantinople.
Selim preluded his campaign by an insolent letter to Shah Ismail. In the course of it he said:—
It is only by the practice of the true religion that a man will prosper in this world and deserve eternal life in the world to come. As for thee, Emir Ismail, such a reward will never be thy lot; for thou hast deserted the path of salvation and of the holy commandment; thou hast denied the purity of the doctrine of Islam; thou hast dishonoured and cast down the altars of God; thou hast by base stratagem alone raised thyself and sprung from the dust—to a seat of splendour and glory; thou hast opened to Mussulmans the gate of tyranny and oppression; thou hast forced iniquity, perjury, and blasphemy to impiety, heresy, and schism; thou hast, under the cloak of hypocrisy, sown in all parts the seeds of trouble and sedition; thou hast raised the standard of ungodliness; thou hast given way to thy shameful passions and abandoned thyself without restraint to the most disgraceful excesses.... Therefore, as the first duty of a Mussulman, and above all of a pious prince, is to obey the commandment, “Oh ye faithful who believe, perform ye the decrees of the Lord”—the ulemas and our teachers of the law have pronounced death against thee, perjurer and blasphemer as thou art, and have laid upon every good Mussulman the sacred duty of taking arms for the defence of religion and for the destruction of heresy and impiety, in thy person and the persons of those who follow thee.
On the approach of Selim and his army to the frontier of Persia, Shah Ismail, instead of going out to meet his foe, laid waste the whole country and retreated towards his capital. This greatly increased the difficulty Selim had of supplying his army. The soldiers were exhausted by the long march. The Janissaries began to murmur. One of the generals, Hemdar Pasha, who had been brought up with Selim from his earliest childhood, and might be expected to have great influence with him, was persuaded by his brother officers to remonstrate with the Sultan against further prosecution of the invasion of Persia, through a country where every vestige of food was destroyed. The Sultan met the suggestion by ordering the instant decapitation of the pasha.
Selim endeavoured to provoke Ismail to meet him in battle by another insolent letter, written mainly in verse, taunting him with cowardice. “One who, by perjury,” he wrote, “seizes sceptres, ought not to skulk from danger.... Dominion is a bride to be wooed and won by him only whose lip blanches not at the biting kiss of the sabre’s edge.” Ismail replied in a dignified letter denying the existence of any reason for war, and expressing willingness to resume peaceful relations. He suggested that Selim’s letter, written in a style so unfitting the dignity of the Sultan, must have been the hasty production of a secretary, who had taken an overdose of opium. The taunt was a bitter one, for it was well known that Selim was addicted to opium. The letter was accompanied by the present of a box of opium to the supposed secretary.
Meanwhile Selim and his army marched on with ever-increasing difficulties of supplies. The soldiers at last broke out in open revolt and demanded to be led back to their homes. Selim took the bold course of riding into the midst of them and addressing them personally.
Is this [he said] your service to your Sultan? Does your loyalty consist of mere boast and lip worship? Let those among you who wish to go stand out from the ranks and depart. As for me, I have not advanced thus far merely to double back on my track. Let the cowards instantly stand aloof from the brave who have devoted themselves with sword and quiver, soul and hand to our enterprise.
He gave word of command to form columns and march, and not a single man dared to leave the ranks.
On the approach of the Ottoman army to Tabriz, Ismail was at last drawn from his reserve. He determined to give battle. The two armies met at Calderan, not far from the capital, on August 14th, 116 days from the commencement of the march, which must have covered nearly twelve hundred miles. This was a great performance on the part of the Turkish army. It was by this time reduced to one hundred and twenty thousand men, of whom eighty thousand were cavalry. The Persian army consisted of eighty thousand cavalry, splendidly mounted and equipped, and well trained. But there were no infantry and no guns. The Turkish soldiers were fatigued by their long march. They were ill-fed and the horses were stale and out of condition. The issue turned upon the success of the charges of the Persian cavalry. They attacked the Turks with great impetuosity in two bodies on either flank. That under command of Ismail himself was successful and broke and dispersed the opposing wing of the Turks. The other column was unsuccessful. The Ottomans fell back behind their guns. The Janissaries formed a solid front. The cannons opened a destructive fire, which was supported by the fire of the Janissaries, who were now armed with muskets. The Persians were shattered and destroyed. The defeat of the other wing of the Turkish army was retrieved. Twenty-five thousand Persian horsemen lay dead on the field. Ismail himself was badly wounded and escaped with difficulty.