In the original Korean version the characters don't have names of the real historic figures. In the subtitled English version most of the characters are given the names of real historic figures by the subtitles authors.
The early working title was Hwatu but the title was changed to prevent confusion with the similarly named playing cards.
The series is based on Empress Gi or Empress Ki (also known as Empress Qi or Öljei Khutuk, a Goryeo-born empress consort of the Yuan dynasty. She was one of the primary empresses of Toghon Temür (Emperor Huizong), and the mother of Biligtü Khan (Emperor Zhaozong), who would become an emperor of the Northern Yuan dynasty.
Ep.29 airs at 22:15 instead of 22:00 because of Winter Olympics. In addition, Ep.30 will not air on February 11, 2014 and instead air on February 17, 2014.
Ep. 19 & 20 of "Empress Ki" originally scheduled to air December 30th and 31st did not air due to award shows and special programming. Ep.19 & 20 will air during the first week of January, 2014.