Baldwin of Boulogne in the context of "Tancred, Prince of Galilee"

Frisian involvement in the Crusades is attested from the very beginning of the First Crusade, but their presence is only felt substantially during the Fifth Crusade. They participated in almost all the major Crusades and the Reconquista. The Frisians are almost always referred to collectively by contemporary chroniclers of the Crusades and few names of individual Frisian crusaders can be found in the historical record. They generally composed a naval force in conjunction with other larger bodies of crusaders.

The first Frisians to participate in the First Crusade were part of the army which was led to the Holy Land by Godfrey of Bouillon and they are only mentioned in passing by Fulcher of Chartres, who mentions that the Frisian language was one of the many tongues spoken by the crusaders. William of Tyre, drawing his information from Fulcher, mentions Frisians as part of the troops led by Godfrey at the Siege of Antioch in 1097–1098. According to Albert of Aix, there was also a fleet of pirates, hailing from Denmark, Frisia, and Flanders and led by Guynemer of Boulogne, who assisted Baldwin of Boulogne at Tarsus.

Thoros (short in Armenian for Theodoros; Թորոս կուրապաղատ, T'oros the Curopalates; d. March 9, 1098) was an Armenian ruler of Edessa at the time of the First Crusade. Thoros was a former officer (curopalates) in the Byzantine Empire and a lieutenant of Philaretos Brachamios. He was Armenian but practiced the Greek Orthodox faith.

The Chronicle of Matthew of Edessa records that "Thoros son of Hethum" was installed as governor of Edessa by Tutush, who had defeated and killed emir Bouzan in the year 543 of the Armenia era (26 Feb. 1094 – 25 Feb. 1095). According to Sturdza, Hethum [I] was descended from the Pahlavouni, an important family in Caucasian Armenia. He conquered land to the east of that conquered by his fellow Armenian Rupen. Steven Runciman calls Thoros the "son-in-law" of Gabriel of Melitene.