Duncan (The True Tragedie of Macbeth)

Donalbain's father, the King of Scotland, was a character in William Shakespeare's play Macbeth.

In an early draft of the play which featured the Doctor, Jamie and Zoe, the titular character, then the Thane of Glamis, was informed by Jamie that he would eventually become both the Thane of Cawdor and the King of Scotland in Act I Scene III. As the Doctor said when he scolded Jamie in Act II Scene III, because Jamie had told Macbeth his destiny he would now want to "slay the King and take his sov'reign throne". (PROSE: The True Tragedie of Macbeth) In the finished version of the play, the trio of the Doctor and his companions was replaced by the Weird Sisters.

In a later scene, Macbeth sent a letter to his wife Lady Macbeth. Upon reading it she realised that, for Macbeth to be King, the present King had to be murdered. (PROSE: The Empire of Glass) She later "put her husband up to it". In the early draft, the Doctor, Jamie and Zoe attempted to prevent this eventuality but arrived at Macbeth's castle too late. They hid and observed as Macbeth, Macduff and Lenox were in conversation with each other. Macduff then entered the King's chambers to wake him up, as he was commanded "to call timely on him", but found him killed. Shouting "Horror! Horror!", he told Macbeth and Lenox to go and see for themselves while he called for Banquo, Malcolm and Donalbain to wake up as well. Believing they might be blamed for the act, the Doctor and his friends slipped away, with Macbeth ultimately framing two guards for the crime. (PROSE: The True Tragedie of Macbeth)

Behind the scenes
The murdered King from Macbeth was largely referred to by his title in both The Empire of Glass and The True Tragedie of Macbeth with neither story naming him as Duncan, though True Tragedie also stated his relationship to Donalbain.