Short answers, pulled from the story.
The Knights Templar were founded in 1118 to protect Christian pilgrims traveling to Jerusalem. This organization served as the first tightly organized military force dedicated to opposing Islamic conquests in the Holy Land.
Bernard of Clairvaux persuaded Pope Eugenius III that conflicts with pagan Wends constituted a holy war analogous to the Reconquista. The new crusaders sought acquisition of new arable lands and serfs along with control of Baltic trade routes.
Jogaila, Grand Duke of Lithuania, routed the Knights at Tannenberg in 1410 following his conversion to Catholicism and marriage to Queen Jadwiga of Poland. Prussia transformed into a secular duchy in 1525 while Livonia followed suit in 1562.
King Dinis I of Portugal created the Order of Christ in 1317 for those knights who survived trials throughout Europe. Only the Order Of Christ can claim descent from the Templars today since it was recognized as the successor organization.
The Sovereign Military Order of Malta has maintained its government seat in Rome since 1834 where it guarantees extraterritorial rights. This lay religious order maintains diplomatic relations with over 100 states and the European Union.