Okay, if you want a proper gateway into C. J. Sansom's world, start with 'Dissolution'—it's where Matthew Shardlake shows up and the Tudor mystery vibe is set. The book throws you into the messy politics of the Dissolution of the Monasteries, with a brilliant slow-burn mystery and a protagonist who grows on you: he's sharp, morally complicated, and often sardonic in a way that kept me turning pages late into the night.
After that, read 'Dark Fire' and then 'Sovereign' in order. The series builds character arcs and recurring threads—you'll appreciate small callbacks and the steady deepening of the historical context. If you want something a bit later and darker, 'Lamentation' and 'Tombland' show Sansom's craft at full tilt: denser plots, richer settings, and an older, wearied Shardlake.
If you're not in the mood for the series, try the standalones: 'Winter in Madrid' (a quieter, atmospheric historical set around the Spanish Civil War) or the provocative alternate history 'Dominion'. Both show Sansom's range beyond Tudor England, and they’re great if you want a one-off experience rather than committing to seven books.