Diana Gabaldon

Held a doctorate in quantitative behavioural ecology and was writing scientific software when she started Outlander purely as practice, with no intention of showing it to anyone. Claire Randall, an army nurse on a second honeymoon in 1945, touches a standing stone and arrives in Scotland in 1743, two years before the Jacobite rising goes wrong.

Gabaldon has kept the series running for decades across very long volumes, mixing historical detail, medicine, and a marriage written over an unusual span of time. Starz adapted it in 2014. Readers argue about where the sequels rank; almost nobody argues about the first one.