William Hartnell fell ill during production and so the script had to be re-written to minimise The Doctor's role in the episode.
The master videotape was wiped by the BBC in 1967. No footage is known to survive. However, director Waris Hussein passed a complete set of telesnaps to the BBC archives in 2004.
Telesnaps and extracts from the original soundtrack, are included as part of a 30-minute abridged reconstruction of the story "Marco Polo". This is included as part of "Doctor Who: The Beginning" DVD collection released in January 2006.
This episode takes place in China in 1289.
This episode was watched by 9.4 million viewers on its original transmission.