Short answers, pulled from the story.
Pope Urban II declared the start of the Crusades on the 27th of November 1095 at the Council of Clermont. This event transformed the traditional penitential journey into a holy war by promising a full remission of sins to those who took up the cross.
The People's Crusade led by Peter the Hermit ended in disaster at the Battle of Civetot on the 21st of October 1096. Seljuk forces under Kilij Arslan I annihilated the crusader host, leaving only a few survivors and leaving a legacy of anti-semitic violence.
The Princes Crusade captured Jerusalem on the 15th of July 1099 under the leadership of Godfrey of Bouillon, Bohemond of Taranto, and Raymond of Saint-Gilles. This campaign established the County of Edessa, the Principality of Antioch, and the Kingdom of Jerusalem.
The Second Crusade launched in 1147 failed due to internal divisions, logistical problems, and a lack of clear strategy. King Louis VII of France and Emperor Conrad III of Germany failed to capture Damascus and were forced to withdraw in disgrace.
Saladin defeated the combined armies of the Crusader states at the Battle of Hattin on the 4th of July 1187. This victory led to the fall of Jerusalem and the collapse of the Kingdom of Jerusalem.
The Crusader states officially ended with the fall of Acre in 1291. This event marked the final collapse of the Crusader states and the beginning of a new era in the history of the Crusades under the Mamluk Sultanate.