The Holy Lance, also known as the Spear of Longinus, the Spear of Destiny, or the Holy Spear, is the lance that pierced the side of Jesus as he hung on the cross during his crucifixion.
One of the soldiers pierced his side with a lance (λόγχη), and immediately there came out blood and water.
— John 19:34
a Roman soldier (named in extra-Biblical tradition as Longinus)
The Bleeding Lance
“The bleeding lance has taken numerous forms throughout the Arthurian literature chronology. In the earlier appearances of the lance, it is not represented as a Christian symbol, but morphs into one over time. In Perceval and Parzival, the lance is described as having "barbaric properties" which are difficult to associate with Christian influence.[10] Chrétien describes his lance with "marvelous destructive powers", which holds a closer connection to the malignant weapons of Celtic origin.[11] In Chrétien's Perceval, the lance takes on a dark and almost evil persona[11] and also seems to overshadow the Grail, which, were this a Christian story, would be rather odd.[12] Wolfram's tale also treated the lance in a similar dark manner. In Parzival, the lance is "poisonous" which contrasts sharply with the general trend of healing Christian themes. This lance is plunged into the Fisher King's wound at different times to continue his pain, as punishment for having sought forbidden love.[10] This lance is considered significant because it is most often associated directly with the wound of the Fisher King, which is demonstrated both in Chrétien's and Eschenbach's versions of the tale.
The more recent writings have the lance presented in the Fisher King's castle with Christian theology. More specifically, it is supposed to be the lance that pierced Jesus Christ while on the cross. This is seen in Malory's Le Morte d'Arthur. In Malory's version, the Fisher King is healed with the blood from the lance, signifying it as a good, holy, Christian object. In Corbenic we see the procession at the Fisher King's feast, featuring heavily on the Holy Grail, which is a strong Christian artifact. It can be extrapolated that in the same procession, the accompanying lance is the lance that pierced Jesus Christ.”
Longinus
Longinus (Greek: Λογγίνος) is the name of the Roman soldier who pierced the side of Jesus with a lance, who in apostolic and some modern Christian traditions is described as a convert to Christianity.[4] His name first appeared in the apocryphal Gospel of Nicodemus.[5] The lance is called in Catholic Christianity the "Holy Lance" (lancea) and the story is related in the Gospel of John during the Crucifixion.[6] This act is said to have created the last of the Five Holy Wounds of Christ.
This person, unnamed in the Gospels, is further identified in some versions of the story as the centurion present at the Crucifixion, who said that Jesus was the son of God,[7] so he is considered as one of the first Christians and Roman converts.
Blindness or other eye problems are not mentioned until after the tenth century.[10] Petrus Comestor was one of the first to add an eyesight problem to the legend and his text can be translated as "blind", "dim-sighted" or "weak-sighted". The Golden Legend says that he saw celestial signs before conversion and that his eye problems might have been caused by illness or age.[11] The touch of Jesus's blood cures his eye problem:
Christian legend has it that Longinus was a blind Roman centurion who thrust the spear into Christ's side at the crucifixion. Some of Jesus's blood fell upon his eyes and he was healed. Upon this miracle Longinus believed in Jesus. - Godwin, Malcolm (1994). The Holy Grail: Its Origins, Secrets & Meaning Revealed