Kilij Arslan I

The People's Crusade (also called the Peasants' Crusade) army of Peter the Hermit and Walter the Penniless arrived at Nicaea in 1096. A German contingent of the crusade overran the castle Xerigordon and held it until Kilij sent a force to starve them out. Those that renounced Christianity were spared and sent into captivity to the east, the rest were slaughtered.[4] Kilij Arslan also cunningly sent spies to trick the Crusaders into thinking Xerigordon was ripe for the taking, and the ill-disciplined Crusaders rushed to Xerigordon despite orders against this. They were consequently ambushed, forcing Peter the Hermit to eventually give up the crusade.

The remainder of Peter's crusade was surprised near the village of Civetot by Kilij Arslan's army. [4] They were easily defeated and around 17,000 out of the 20,000 remaining Christian's died. [5] He then invaded the Danishmend Emirate of Malik Ghazi in eastern Anatolia.

The First Crusade will start a few months later.

Because of this easy first victory he did not consider the main crusader army, led by various nobles of western Europe, to be a serious threat. He resumed his war with the Danishmends, and was away from Nicaea when these new Crusaders besieged Nicaea in May 1097. He hurried back to his capital to find it surrounded by the Crusaders, and was defeated in battle with them on May 21. The city then surrendered to the Byzantines and his wife and children were captured. When the crusaders sent the Sultana to Constantinople, to their dismay she was later returned without ransom in 1097 because of the relationship between Kilij Arslan and Alexius Comnenus.

As result of the stronger invasion, Rüm and the Danismends allied in their attempt to turn back the crusaders. The Crusaders continued to split their forces as they marched across Anatolia. The combined Danishmend and Rüm forces planned to ambush the Crusaders near Dorylaeum on June 29. However, Kilij Arslan's horse archers could not penetrate the line of defense set up by the Crusader knights, and the main body under Bohemond arrived to capture the Turkish camp on July 1. Kilij Arslan retreated and inflicted losses on the Crusader Army with guerilla warfare and hit-and-run tactics. He also destroyed crops and water supplies along their route in order to damage logistical supplying of the Crusader Army.

See also: Siege of Nicaea, Battle of Dorylaeum

Crusade of 1101

Ghazi bin Danishmend captured Bohemond resulting in a new force of Lombards attempting to rescue him. In their march they took Ankara from Arslan upon the Danishmends. In alliance with Radwan the Atabeg of Aleppo he ambushed this force at the Battle of Mersivan. In 1101 he defeated another Crusader army at Heraclea Cybistra, which had come to assist the fledgling Crusader States in Syria. This was an important victory for the Turks, as it proved that an army of Crusader knights was not invincible. After this victory he moved his capital to Konya and defeated a force led by William II of Nevers who attempted to march upon it as well as the subsequent force a week later.

In 1104 he resumed once more his war with the Danishmends who were now weakened after the death of Malik Ghazi, demanding half the ransom gained for Bohemond. As a result, Bohemond allied with the Danishmends against Rüm and the Byzantines.