The Second Crusade

German route
The German crusaders, accompanied by the papal legate and cardinal Theodwin, intended to meet the French in Constantinople. Ottokar III of Styria joined Conrad at Vienna, and Conrad's enemy Geza II of Hungary allowed them to pass through unharmed. When the German army of 20,000 men arrived in Byzantine territory, Manuel feared they were going to attack him, and Byzantine troops were posted to ensure that there was no trouble. There was a brief skirmish with some of the more unruly Germans near Philippopolis and in Adrianople, where the Byzantine general Prosouch fought with Conrad’s nephew, the future emperor Frederick. To make things worse, some of the German soldiers were killed in a flood at the beginning of September. On 10 September, however, they arrived at Constantinople, where relations with Manuel were poor and the Germans were convinced to cross into Asia Minor as quickly as possible. Manuel wanted Conrad to leave some of his troops behind, to assist in defending against attacks from Roger II, who had taken the opportunity to plunder the cities of Greece, but Conrad did not agree, despite being a fellow enemy of Roger.[19] In Asia Minor, Conrad decided not to wait for the French, and marched towards Iconium, capital of the Seljuk Sultanate of Rüm. Conrad split his army into two divisions. The king led one of these, which was almost totally destroyed by the Seljuks on 25 October 1147 at the second battle of Dorylaeum.[20]

In battle, the Turks used their typical tactic of pretending to retreat, and then returning to attack the small force of German cavalry which had separated from the main army to chase them. Conrad began a slow retreat back to Constantinople, and his army was harassed daily by the Turks, who attacked stragglers and defeated the rearguard. Even Conrad was wounded in a skirmish with them. The other division, led by the King's half-brother, Bishop Otto of Freising, had marched south to the Mediterranean coast and was similarly defeated early in 1148.[21]

http://en.wikipedia.org/wiki/Second_crusade