The First Crusade: Road to Jerusalem

In November 1095 Pope Urban II held a ten-day church council at Clermont in the Auvergne, with some twelve archbishops, eighty bishops and ninety abbots. Most of its business was church discipline. But on 27 November, before a crowd of clergy and laymen gathered in a field outside the town, he called on Christians to help the Byzantines against the Turks and to free the holy places. The response was far bigger than he expected. Preachers spread the call; one, Peter the Hermit, led a disorderly People's Crusade that attacked Jewish communities in the Rhineland.

Location precision: Urban spoke in a field outside the medieval town whose site is not known; the pin marks Clermont's cathedral square.

Visitor guidance: Clermont-Ferrand's black lava-stone cathedral and the Romanesque basilica of Notre-Dame-du-Port are a short walk apart in the old town.

Between November 1096 and April 1097 the princes' armies — Godfrey of Bouillon's Lorrainers, Raymond of Toulouse's Provençals, Bohemond's southern Italian Normans and others — gathered outside the land walls of Constantinople, short of food. Emperor Alexios I, who had moved his residence to the Blachernae palace at the walls' northern end, was wary, above all of Bohemond, an old enemy. In return for supplies he demanded an oath to return any former Byzantine lands. Godfrey swore first; Raymond alone refused. Then Alexios ferried them across the Bosphorus.

Location precision: The armies camped along the land walls; the pin marks the Blachernae quarter.

Visitor guidance: Long stretches of the Theodosian land walls survive in western Istanbul and can be walked from Ayvansaray to Yedikule.

The first target was Nicaea, capital of the Seljuk sultan Kilij Arslan, which the Turks had taken from Byzantium in 1081. The crusaders besieged it from 14 May 1097, but the city was supplied across its lake. Alexios had boats dragged overland to blockade the water, and his general Manuel Boutoumites quietly negotiated a surrender. On 19 June the Turks surrendered to the Byzantines, not to the crusaders, who were furious to be denied their plunder. The city's Roman walls, with more than 100 towers, still ring the modern town of İznik.

Visitor guidance: The ruined city walls and gates make a pleasant walk around İznik; the former Hagia Sophia stands in the centre.

Marching on in two groups, the crusaders made camp on 30 June by a river near the ruined town of Dorylaion. At dawn on 1 July Kilij Arslan's mounted archers surrounded the Norman vanguard under Bohemond, which had marched ahead of the rest. When the second army arrived, Godfrey broke through the Turkish lines and Bishop Adhemar attacked from behind, and the Turks fled. The road across Anatolia was open, but a hard summer march lay ahead.

Location precision: The battlefield's exact site is uncertain; the pin marks the area of ancient Dorylaion, now Eskişehir.

Antioch was too large to surround. From 20 October 1097 the crusaders besieged it through a winter of famine. In early June 1098 an Armenian officer, Firouz, let Bohemond's men over a section of wall, and the city's Christians opened the gates. Days later a huge relieving army under Kerbogha of Mosul trapped the crusaders inside. Then a peasant visionary claimed to have found the Holy Lance, and on 28 June the starving army marched out and routed Kerbogha. Bohemond kept Antioch for himself.

Location precision: The siege surrounded the whole city; the pin marks the Cave Church of St Peter on the mountainside above Antakya, which the crusaders extended.

While the leaders quarrelled over Antioch, the crusade stalled for months. In December 1098 Raymond's army besieged and took the small Syrian town of Ma'arrat al-Numan, killing many of its inhabitants. Some Latin chroniclers wrote that starving soldiers then ate the bodies of the dead — an episode that does not appear in Muslim sources and that historians still discuss. In January 1099 Raymond had the town walls pulled down and set off south towards Jerusalem barefoot, dressed as a pilgrim.

Raymond, hoping to win a state of his own around Tripoli, besieged the fortress town of Arqa from 14 February 1099, and the other leaders reluctantly joined him. Morale sank. Rival clergy accused the visionary Peter Bartholomew of faking the Holy Lance, and on 8 April he walked through fire to prove it; he died of his burns days later, and with him went much of Raymond's prestige. On 13 May the army gave up and marched on down the coast, the emir of Tripoli supplying horses to be rid of them.

Location precision: The pin marks the ancient mound of Tell Arqa, where the medieval town stood.

On 7 June 1099 the crusaders reached Jerusalem, held by the Fatimids of Egypt, too few to blockade it. Genoese sailors brought timber for siege towers, and after a fast and a procession to the Mount of Olives the armies attacked from north and south. On 15 July the northern wall was taken, and the crusaders killed a great part of the city's Muslims and Jews; some historians think later chroniclers exaggerated the numbers. Godfrey of Bouillon was elected ruler, taking the title Defender of the Holy Sepulchre rather than king.

Location precision: The assault came over the northern wall near today's Herod's Gate, which the pin marks.