After conquering Jerusalem on June 15, 1099, Godfrey refused to become King of Jerusalem, instead choosing the title of Protector of the Holy Sepulcher. Some sources suggest that Godfrey was at least helpful to the foundation of the Order of the Temple or a precursor of that Order. It seems probable that Godfrey established an early Order in the Holy Land: the Order of the Holy Sepulcher.
Apparently he gathered around him twelve knights. These knights were to protect the religious chapter of Canons Regular of the Holy Sepulcher, whcih probably already served, be it not als an Order, at the Sepulcher when Godfrey and his army arrived. It is generally acknowledged that there indeed was already a religious order of Canons of the Holy Sepulcher under the rule of Saint Augustine prior to the conquest of Jerusalem.
Godfrey supposedly established his knightly Order of the Holy Sepulcher in 1099, shortly after the conquest of Jerusalem. The present day Equestrian Order of the Holy Sepulcher indicates that according to undocumented tradition its origin can be traced back to the First Crusade, so around 1099. Sometimes the year 1103 is mentioned. The first year falling during the reign of Godfrey, the second being after Godfrey's death and at the time of King Baldwin I.
Some researchers suggest that the origins of the Temple can be found in the associations that the Knightly Order of the Sepulcher formed with the Order of the Canons Regular of the Holy Sepulcher. It seems this group may have been known as the “Milites Christi,” or “Milites Sancti Sepulchri”, later to be known as the Knights Templar.
The chronicler Bernard the Treasurer emphasized the Templars connection with the Holy Sepulcher. This connection includes the facts that the Templars’ liturgy was that of the Holy Sepulcher, that the “French rule” (dating to 1140) stated that it was “l’ordinaire del Sepulchre,” and that the peculiar, often polygonal, way that Templars built their churches was inspired by the polygonal Church of the Holy Sepulcher.
source: The Templar Papers, Oddvar Olsen, 2006; Illustration: Godfrey of Bouillon, from a fresco painted by Giacomo Jaquerio in Saluzzo, northern Italy, around 1420, source Wikipedia