When Selim starts his march east in summer 1514, the Safavid realms are invaded in the east by the Uzbek state recently brought to prominence by Abu 'I-Fath Muhammad, who had fallen in battle against Ismail only a few years before.
To avoid the prospect of fighting a war on two fronts, Isma'il employs a scorched earth policy against Selim in the west.
The terrain of eastern Anatolia and the Caucuses is extremely rough and combined with the difficulty in supplying the army in light of Isma'il's scorched earth campaign while marching against Muslims, Selim's army is discontent.
The Janissaries even fire their muskets at the Sultan's tent in protest at one point.
When Selim learns of the Safavid army forming at Chaldiran, on the eastern side of the Euphrates River, northeast of Lake Van, hee quickly moves to engage Isma'il in part to stifle the discontent of his army.
While the Safavid forces are at Chaldiran and planning on how to confront the Ottomans, Muhammad Khan Ustajlu, who serves as the governor of Diyabakir, and Nur-Ali Khalifa, a commander who knows how the Ottomans fight, proposes that they should attack as quickly as possible.
However, this proposal is rejected by the powerful Qizilbash officer Durmish Khan Shamlu, who rudely says that Muhammad Khan Ustajlu is only interested in the province that he governs.
The proposal is also rejected by Ismail himself, who says, "I am not a caravan-thief, whatever is decreed by God, will occur."
Selim, taking precautions against followers of the Shah among his own troops, orders an immediate attack on August 23 and with superior weapons and tactics, wins an overwhelming Ottoman victory.
Ismail's army is more mobile and their soldier are better prepared, but the Ottomans prevail, due in large part to their efficient modern army, and possession of artillery, black powder and muskets.
Ismail is wounded and almost captured in battle.