Greg Jenner is joined by special guests Stephen Fry and Dr Bodie Ashton as they travel back to 18th-century Prussia to meet Frederick the Great.

Widely known for making Prussia a military power while modernising and liberalising culture, Frederick was a complicated character, shaped by a tragic childhood ruled by his cruel father. We uncover why he wasn’t the greatest ally to neighbouring countries, and why forks enraged his father - and answer the crucial question of whether it's King of Prussia or King in Prussia.

Written and produced by Emma Nagouse and Greg JennerAssistant Producer: Emmie Rose Price-GoodfellowResearch by Claudia TreacherProject Management: Siefe MiyoAudio Producer: Abi Paterson

The Athletic production for BBC Radio 4