The history of Indian Restaurants in Britain, vampires, and fortune telling are the three topics on the table when the UK’s quirkiest podcast celebrates its 100th episode today.

       The Rabbit Hole Detectives, starring Charles Spencer, the Rev Richard Coles, and Norwegian archaeologist Cat Jarman, has become wildly popular with its lopsided look at the past.

       Every week each of its three voraciously inquisitive presenters tackles a topic – taking listeners down rabbit holes of history and fiction with topics varying from Time Zones to the Erfurt Latrine Disaster, and the Exploding Whale of Oregon to the history of the Paperclip.

       The trio came up with the idea after finding a shared love of the strange while chatting round a table at Spencer’s ancestral home, Althorp.

       “This all started when Charles, Richard and I were chatting round a table at Althorp,” says Jarman. “We talked about weird and wonderful stuff, and I suggested we record it for a podcast. Little did I think that’d lead to 100 episodes– with many more in the offing!"

       Coles and Spencer first met at a social event in Northamptonshire where the earl was a deputy lieutenant of the county and Coles was the high sheriff’s chaplain. Spencer and Jarman, now a couple, became acquainted when she was searching for an ancient village in Althorp’s grounds for a Channel 4 documentary.

       “I love it when we hear from listeners around the world who say how much they look forward to Wednesdays, when the three of us help to put a smile on their face,” says Spencer, younger brother to the late Princess Diana. “People battling cancer, or slogging through other hugely challenging ordeals, have said the Rabbit Hole Detectives give them a lift – and that's just wonderful.”

       The Rev Coles, former musician in The Communards turned broadcasting national treasure, adds: “We’ve barely drawn breath.”