1081 CE - 1118 CE: Reign of Byzantine emperor Alexios I Komnenos.

1088 CE - 1099 CE: Reign of Pope Urban II.

1095 CE - 1102 CE: The First Crusade is formed to recapture Jerusalem for Christendom. It is successful in its primary aim.

1095 CE: Byzantine emperor Alexios I Komnenos appeals to the west for aid against the Seljuks.

1095 CE: At the Council of Clermont, Pope Urban II calls for the First Crusade to form and retake Jerusalem for Christendom.

1096 CE: The people's army led by Peter the Hermit departs for Constantinople during the First Crusade.

1096 CE: The 'People's Crusade' is wiped out near Nicaea by a Seljuk army.

1096 CE: The "People's Crusade" led by Peter the Hermit is wiped out by a Seljuk army near Nicaea.

1097 CE: The First Crusaders arrive at Constantinople.

1097 CE: The First Crusaders capture Nicaea.

1097 CE: A Crusader army wins a great victory against a Muslim army at Dorylaion.

1098 CE: Baldwin of Boulogne takes control of Edessa and the County of Edessa is formed, one of four Crusader-created states in the Levant.

1098 CE: The First Crusaders capture Antioch after an 8-month siege.

1098 CE: The Crusaders defeat a large Muslim army sent to recapture Antioch.

1099 CE: The Crusader army arrives at the walls of Jerusalem, the objective of the First Crusade.

1099 CE: A small fleet of Genoese and English ships arrives at Jaffa bringing essential supplies for siege weapons to the First Crusaders at Jerusalem.

1099 CE: Siege towers are built by the First Crusaders to better attack Jerusalem.

1099 CE: Jerusalem is captured during the First Crusade.

1099 CE: A Muslim army is sent to recapture Jerusalem but is defeated by the Crusaders at the battle of Ascalon.

1101 CE: Caesarea is captured by the Crusaders.

1101 CE: Acre is captured by the Crusaders.

1130 CE: Albert of Achen's account of the First Crusade, the 'Jerusalem History", is written based on soldiers accounts.