According to The Twilight Saga: The Official Illustrated Guide, he, Makenna, and Renata came from a vampire-friendly Maltese family that worked together to preserve their family line. He was converted into a vampire around 400 BC. Unlike most vampires, Luca did not leave his family behind; he continued to look after his family's prosperity and safety. With a vampire on their side, the family prospered greatly. Everyone in the family was in on the secret and thought of Luca as a kind of 'personal' family saint.
One of Luca's relatives, a distant nephew, joined him, but later chose to go on his own rather than staying a part of the family, which disappointed Luca. He then looked for another family member to help him preserve the family line, and turned a few more of his relatives into vampires, two of which became his constant companions while others left the family for various reasons.
When the Volturi came to offer Renata, one of Luca's descendants, a place within the guard, Luca encouraged her to take up on their offer in order to avoid conflict; he was in enough trouble as it was due to his family's knowledge of real vampires. He continued to look after his family's prospects. Eventually, it became a family tradition for Luca to choose one descendant or two to change into vampires every other century.
When Makenna, one of the chosen ones, fell in love with a man named Charles, Luca reasoned that she could indeed abandon her destiny to be with him as a human, but she decided to follow it through anyway. A few years later, Charles joined their family as a vampire. Makenna changed him personally, knowing Luca would never change someone outside of the family.
From description, Luca seems to be a generous, devotive and family-motivated person. Though he chooses one family member to be changed into a vampire every few centuries, he would respect that chosen one's wishes if he or she chooses otherwise. He dedicates his entire existence to providing for his family and maintaining the thin secrecy of vampirism.
Luca is only mentioned in The Twilight Saga: The Official Illustrated Guide.
|Current nomads||Alistair • Boris • Charles • Charlotte • Fred • George • Huilen • Jennifer • Joham • Luca • Makenna • Mary • Maysun • Nahuel • Peter • Randall • Serena • Shelly • Steve • Toshiro|
|Former nomads||Cold Man • Cold Woman • Garrett • James • Laurent • Victoria|