Conrad III of Germany in the context of "Duchy of Franconia"

The second Battle of Dorylaeum took place near Dorylaeum in October 1147, during the Second Crusade. It was not a single clash but consisted of a series of encounters over a number of days. The German crusader forces of Conrad III were defeated by the Seljuk Turks led by Sultan Mesud I.

The Second Crusade (1147–1149) was the second major crusade launched from Europe. The Second Crusade was started in response to the fall of the County of Edessa in 1144 to the forces of Zengi. The county had been founded during the First Crusade (1096–1099) by the future King Baldwin I of Jerusalem in 1098. While it was the first Crusader state to be founded, it was also the first to fall.

The Second Crusade was announced by Pope Eugene III, and was led in the east by European kings Louis VII of France and Conrad III of Germany, with help from a number of other European nobles. The armies of the two kings marched separately across Europe. After crossing Byzantine territory into Anatolia, both armies were separately defeated by the Seljuk Turks. The main Western Christian source, Odo of Deuil, and Syriac Christian sources claim that the Byzantine Emperor Manuel I Komnenos secretly hindered the crusaders' progress, particularly in Anatolia, where he is alleged to have deliberately ordered Turks to attack them. However, this alleged sabotage of the Crusade by the Byzantines was likely fabricated by Odo, who saw the Empire as an obstacle; moreover, Emperor Manuel had no political reason to do so. Louis and Conrad reached Jerusalem in 1148, where the remnants of their armies participated in an ill-advised attack on Damascus that ended in their retreat. Crusader efforts were successful in Iberia, where several territories—including Lisbon, the future capital of the Portuguese Empire—were conquered.

Géza II (Hungarian: II. Géza; Croatian: Gejza II.; Slovak: Gejza II.; 1130 – 31 May 1162) was King of Hungary and Croatia from 1141 to 1162. He was the oldest son of Béla the Blind and his wife, Helena of Serbia. When his father died, Géza was still a child and he started ruling under the guardianship of his mother and her brother, Beloš. A pretender to the throne, Boris Kalamanos, who had already claimed Hungary during Béla the Blind's reign, temporarily captured Pressburg (now Bratislava in Slovakia) with the assistance of German mercenaries in early 1146. In retaliation, Géza who came of age in the same year, invaded Austria and routed Henry Jasomirgott, Margrave of Austria, in the Battle of the Fischa.

Although the German–Hungarian relations remained tense, no major confrontations occurred when the German crusaders marched through Hungary in June 1147. Two months later, Louis VII of France and his crusaders arrived, along with Boris Kalamanos who attempted to take advantage of the crusade to return to Hungary. Louis VII refused to extradite Boris to Géza, but prevented the pretender from contacting his supporters in Hungary and managed to shepherd him to Constantinople with the rest of the crusaders. Géza joined the coalition that Louis VII and Roger II of Sicily formed against Conrad III of Germany and Byzantine emperor Manuel I Komnenos.

The Chronica regia Coloniensis ("Royal Chronicle of Cologne", German: Kölner Königschronik), also called the Annales Colonienses maximi, is an anonymous medieval Latin chronicle that covers the years 576 to 1202. The original chronicle only went up to 1197, but a continuator later added the following few years' events. Further continuators in the 13th century extended it down to 1249. According to the historian Manfred Groten, the Chronica was probably first compiled about 1177 in Michaelsberg Abbey, Siegburg, and then continued in Cologne. The earliest manuscript only contains an account down to 1175.

The chronicle is called "royal" because it is a history of the Roman emperors, Frankish kings, Byzantine emperors and German kings and emperors. It probably began with Augustus, but the beginning of the chronicle is lost. Up to 1106 the Chronica depends on the works of Frutolf von Michelsberg and Ekkehard of Aura, and then on until 1144 on the now lost Annales Patherbrunnenses. After that it is an independent source. The author of the Chronica sancti Pantaleonis made use of the royal chronicle to cover the years down to 1199, and the historian Georg Waitz treated the former as a mere continuation of the latter and edited them together.

Frederick Barbarossa was elected King of Germany on 4 March 1152 in Frankfurt am Main. Frederick's uncle, Otto of Freising, was an eyewitness and is the most important source for the 1152 election. According to him, "the entire company of the princes ... from the immense extent of the transalpine realm (as well as certain barons from Italy)" met in Frankfurt by early March to elect a successor to King Conrad III, who had died barely two weeks earlier at Bamberg on 15 February 1152. Only five days after his election, on 9 March, Frederick was crowned in the Aachen Chapel.

The apparent quickness of the election of 1152 contrasts with those of 1125 and 1138. In his own letter to Otto of Freising listing the accomplishments of his first five years on the throne, Frederick does not mention his election, but says only that "we were anointed at Aachen and received the crown of the German realm." According to Otto, Conrad had on his deathbed designated Frederick as his choice of successor, because he knew that the princes would not elect his young son, Frederick. He then entrusted his son and the royal insignia to Frederick.

Frederick II (German: Friedrich II, 1090 – 6 April 1147), called the One-Eyed (der Einäugige), was Duke of Swabia from 1105 until his death, the second from the Hohenstaufen dynasty. His younger brother Conrad was elected King of the Romans in 1138.

The siege of Damascus took place between 24 and 28 July 1148, during the Second Crusade. It ended in a crusader defeat and led to the disintegration of the crusade. The two main Christian forces that marched to the Holy Land in response to Pope Eugene III and Bernard of Clairvaux's call for the Second Crusade were led by Kings Louis VII of France and Conrad III of Germany. Both faced disastrous marches across Anatolia in the months that followed, with most of their armies being destroyed. The original focus of the crusade was Edessa (Urfa), but in Jerusalem, the preferred target of King Baldwin III and the Knights Templar was Damascus. At the Council of Acre, magnates from France, Germany, and the Kingdom of Jerusalem decided to divert the crusade to Damascus.

The crusaders decided to attack Damascus from the west, where orchards of Ghouta would provide them with a constant food supply. Having arrived outside the walls of the city, they immediately put it to siege, using wood from the orchards. On 27 July, the crusaders decided to move to the plain on the eastern side of the city, which was less heavily fortified but had much less food and water. Afterwards, the local crusader lords refused to carry on with the siege, and the three kings had no choice but to abandon the city. The entire crusader army retreated back to Jerusalem by 28 July.

Lothair III, sometimes numbered Lothair II and also known as Lothair of Supplinburg (c. June 1075 – 4 December 1137), was Holy Roman Emperor from 1133 until his death. He was appointed Duke of Saxony in 1106 and elected King of Germany in 1125 before being crowned emperor in Rome. The son of the Saxon count Gebhard of Supplinburg, his reign was troubled by the constant intriguing of the Hohenstaufens, Duke Frederick II of Swabia and Duke Conrad of Franconia. He died while returning from a successful campaign against the Norman Kingdom of Sicily.