|Relationships:||The Cahill Family|
|First Appears In:||Vespers Rising|
|Last Appears In:||Vespers Rising|
Luke Cahill was the oldest of the five Cahill siblings. He was born in 1484 and was the founder of the Lucian Branch (although his death is unknown). He was the eldest and was never satisfied with his portion of the Clues. He needed all of the 39 Clues for his father's secret formula to make it happen. But, when his siblings falsely accused him of starting the fire that burnt down the family home and killed their father, he became more focused on revenge and destroying his siblings than his own dream. So he left Ireland and went to England, where he became the rising star of King Henry VIII's court. Court life educated him that anything was not out of reach as long as one is willing to use bribery, blackmail, and other forms of "persuasion." So Luke started to send spies to track his siblings and even told them to do whatever it takes to find their Clues.
Before he went to London, there was a rumor that he had a diary containing what he knew, including what really happened at the fire. It is said that he gave it to someone he thought would be a good idea to trust; his sister, Jane. She hid it in an unknown location for a reason not explained in the books. Luke was the only one of the other four siblings that Jane got along with on occasion. He is the only sibling known to have confrontations directly with Damien Vesper and Madeleine Cahill.
"Revenge above all"
- Gideon Cahill - Father (deceased)
- Olivia Cahill - Mother (deceased)
- Thomas Cahill - Brother (deceased)
- Katherine Cahill - Sister (deceased)
- Jane Cahill - Sister (deceased)
- Madeleine Cahill - Sister (deceased)
- Louisa - (Sister-in-Law) (deceased)
- Winthrop Cahill - Son (deceased)
- Toyotomi Hideyoshi - Nephew (deceased)
- William Shakespeare - Great x2 Nephew (deceased)
- Keiko - (Sister-in-Law) (deceased)
- Madeleine the Matriarch - Great x2 Grandmother (deceased)
- Mary Arden - Niece (deceased)
- Every other Cahill ever to be born; all influential and famous historical figures for roughly the last 500 years.
- Wife (name unknown)
Appearance and PersonalityLuke Cahill is described as a thin, cruel looking man with dark hair like Dan. He is also said to be "sneakier than a serpent and even more deadly" by his younger sister, Katherine. He is also said to be at the wrong place at the wrong time by his Lucian fellow agents.
He appears on an old Irish portrait in the French catacombs with his siblings.
In Venice, Amy dreams of his portrait back in France.
Gideon gives all the siblings their serums. Luke immediately takes his portion and in the evening comes to warn his father that Damien Vesper and his men are coming. After rescuing all the siblings he gets blamed for the fire by Katherine and Thomas and leaves to go to London. He later finds Madeleine and appoints her governess for his son, Winthrop Cahill, but eventually attempts to execute her, but she escapes.
- Strategy and planning (effects of the Lucian serum)
He does not appear online except on his card when you enter it.
- He had a dagger found by Sir Isaac Newton.
- He was the only Cahill child (besides Madeleine) who was certain Lord Vesper set the fire. It has been theorized that Jane believes this as well, due to her love and trust of Luke.
- Luke became the adviser of the king of England, King Henry VIII.
- He and his mother are the only Cahills to speak directly to Madeleine Cahill and Damien Vesper
- He was the only Cahill child who was with Gideon for some time before his death.