The closely watched hearings that lasted more than three weeks featured an irritible Brown in the witness box, debate about the Merovingian monarchy, the Knights Templar and Jesus' bloodline, and revelations about the media-shy author and his wife, Blythe.
The Da Vinci Code, one of the most successful novels of all time with sales of more than 40 million copies, uses some of the same ideas as The Holy Blood and the Holy Grail, a 1982 work of historical conjecture by Michael Baigent and Richard Leigh.
Both books raise the possibility that Jesus had a child by Mary Magdalene, that she fled to France after the crucifixion and that Christ's bloodline survives to this day.
They also associate Magdalene with the Holy Grail.
Baigent and Leigh, who have been in court throughout the case, are suing Brown's British publisher Random House, which also happens to be their own.
Jonathan Rayner James, lawyer for Baigent and Leigh, said: "He (Brown) and/or Blythe has intentionally used HBHG in order to save the time and effort that independent research would have required."
Richard Leigh (L) and Michael
Baigent (R) are suing the publisher
The third author of the Holy Blood book, Henry Lincoln, is not part of the legal action.
In his closing submission, Rayner James tried to play down fears that victory for the historians would limit the extent to which novelists can draw on sources, historical or otherwise.
Blythe Brown emerged as a key figure in the case, collecting research material before her husband wrote the novel and arguing for the inclusion of some of its most important themes.
Rayner James said Blythe's evidence was of "fundamental importance" to the case.
"It was crucial in revealing the dependency on HBHG and the extent to which she relied upon it," he said. "Perhaps that explains why she was not produced."
Dan Brown, who was not in court on Monday but spent three days under cross-examination last week, has said he wanted to keep his wife away from the media spotlight.
The lawyer criticised Brown, 41, for being vague about dates and sources.
Dan Brown (L) had been accused
of plagiarism before
He also admitted his own client Baigent had been "a poor witness".
The historians argue that Blythe must have referred to the Holy Blood book before Brown wrote his synopsis for The Da Vinci Code in January 2001, contrary to his witness statement.
Copyright lawyers believe the historians may struggle to convince the judge they can copyright general ideas.
Not the first
It is not the first time Brown has been accused of plagiarism.
In August he won a court ruling against Lewis Perdue, who alleged The Da Vinci Code copied elements of two of his novels, Daughter of God and The Da Vinci Legacy.
The losing side in the current case faces over one million pounds ($1.75 million) in legal costs, though the publicity has caused a spike in sales of the Holy Blood book.
Also set to benefit from the media coverage is the Hollywood movie of The Da Vinci Code, starring Tom Hanks, out in May; the release of the US paperback edition of the novel on 28 March, and Baigent, whose book The Jesus Papers is due out next week.