Geoffrey de Lacy

Sir Geoffrey de Lacy was an English knight and a cousin of Ranulf Fitzwilliam.

Biography
In March 1215, de Lacy went to London to swear the Crusader's Oath before King John of England. On his journey back to Fitzwilliam Castle, he met with Sir "Gilles Estram" — in reality, — who had him arrested and taken before Kamelion, who was in the guise of the King. De Lacy was naturally perplexed as to how His Majesty could be in London and at the castle at the same time.

The King freed de Lacy in favour of executing Estram, but the Fifth Doctor ordered him taken down to the dungeons. This was a ploy so de Lacy could show the Doctor the way. Once they arrived, he was freed.

The Doctor told de Lacy to return to London and warn the real King. As he rode from the castle, a guard — acting on the Master's orders — shot him in the back with a crossbow. The mortally wounded de Lacy was returned to the castle where he uttered the words "The King... Doctor... Seek..." before he died. (TV: The King's Demons)