Songfacts®:

• This song was originally something Charli was working on with Rostam Batmanglij of Vampire Weekend. The two started writing it after seeing Miley Cyrus play the Staples Center and then getting drunk. "We went back to his house and I sat on top of [Batmanglij's] piano, and we wrote 'Kingdom,'" Charli told Pitchfork. "We sung it into his phone. I remember thinking in the morning, 'Ugh, this is going to be the worst thing ever,' but it was really good."
  
  The tune remained as a drunken voice note on their phones until Hunger Games Mockinjay soundtrack curator Lorde called Charli up and asked her to lend a song to the movie. The English songstress figured out "Kingdom" would fit well.
• Lorde asked asking Charli if she wanted to "put a legend on the song as well." Among her suggestions were Duran Duran's Simon Le Bon, who ended up supplying a brief vocal at the end of the track. "[Le Bon] cut his vocal in New York with Rostam, so we were never in the studio together," Charli told Radio.com. "But we had an email chain going, which was awesome. He sounds incredible, it's really cool to work with someone who's such a legend."