Doctor Who: The Newbies Guide
The Empire of Glass
This is the sixteenth in the Missing Adventures series of novels published by Virgin.
At one point it was available as a free ebook on the BBC website.
Where does this fit?
This happens between Season 2's final story (The Time Meddler) and Season 3's first (Galaxy 4). It is immediately after the first Doctor is snatched by the Time Lords for the events of The Three Doctors.
Other Guides to this Story
The first Doctor looks like a human in his sixties. He is physically quite frail, but has a keen intellect. He is paternalistic towards his companions, and has a degree of arrogance towards others. He sometimes forgets his companions' names.
Steven Taylor was a space pilot, possibly from the late 22nd Century, who crashed on the planet Mechanus. Steven was held captive by the Mechanoids for three years, his only companion being a stuffed panda. When the Doctor arrived on the planet in The Chase he stowed away on the TARDIS.
Vicki Pallister is a teenager who was on board a spaceship which crashed on the planet Dido. The other survivors were killed off by one of the survivors called Bennett, who was posing as an alien called Koquillion. In The Rescue she was rescued by the Doctor, who offered her a place on board the TARDIS. He treated her like a replacement for his granddaughter Susan.
Recurring and Historical Characters
Irving Braxiatel is a Time Lord who has a long history with the Doctor. He first appeared in the New Adventures novel Theatre of War where his Braxiatel Collection was one of the biggest stores of information and artefacts in the galaxy. For Irving, that story takes place long after this one.
William Shakespeare was England's (and probably the world's) most famous playwright, Shakespeare wrote a number of very well-known plays in the Elizabethan and Jacobian eras. The Doctor has met him on a number of occasions, though all of those are later in the Doctor's timeline than this story.
Gallileo Gallilei was one of the key figures in the birth of science. He is most famous for his theory that the Earth revolves around the Sun, rather than the Sun revolving around the Earth. He is also credited as the inventor of the telescope.
Christopher Marlowe was a playwright and contemporary of William Shakespeare, Marlowe was (supposedly) killed in a pub duel.
Cardinal Bellarmine was a real church official of the time. You don't really need to know anything about him.
Familiar alien species attending the weapons limitation conference include Sontarans (seen in numerous stories starting with The Time Warrior), their long-time enemies the Rutan (seen in Horror of Fang Rock) and the Ice Warriors (seen in numerous stories starting with The Ice Warriors. But you don't need to know anything about their backgrounds.
There's nothing essential, but the following Classic Series stories flesh out some of the background for you:
In The Chase Vicki saw Shakespeare on the Time-Space Visualiser, a machine in the TARDIS that shows real events. In City of Death the fourth Doctor mentions that he helped Shakespeare write the play Hamlet.
In The Three Doctors, the first Doctor was taken out of his timestream by Time Lords from the future. He met his second and third selves, whom he described as "a dandy and a clown".
The author's notes which used to be on the BBC website provide lots of useful background information.
If you want a bit more background on Irving Braxiatel then you might want to read the New Adventure Theatre of War.