Montaillou
Montaillou was a tiny, poor, unimportant village in the sheep-herding region of the Ariege in the twelfth century. Its only claim to fame was being one of the last pockets of Catharism in the area. As part of a network of family feuds among several households in the village, people were constantly accusing each other of being heretics, and having their enemies hauled down to Foix to be examined by the Inquisition, which at that time was being run by a young cleric named Jacques Fournier -- who would later become Pope Benedict XII.
Fournier's method of examining accused heretics was unique -- he asked them endless questions about their daily lives, waiting for inconsistencies and slip-ups that might later be developed into admission of wrong-doing or full-blown confessions. So he asked people what day they did laundry, and how they passed their evenings during lambing time, and who came to visit the night Junior announced his engagement to the girl next door. After several years of going back to Montaillou again and again to investigate accusations of heterodoxy, Fournier grew so disgusted with the quarrelsome Montaillouians, that one day he rounded up everyone in the community over the age of thirteen, and brought them down into Foix to be examined and certified as either heretic or orthodox, once and for all.
The documents of these examinations provide a fascinating glimpse into the life of a medieval community, as well as vivid individual portraits -- people's likes and dislikes, daily routines, status seeking, even their sexual adventures (that Beatrice de Planissoles was positively buttering the Pyrenees with it!). The great social historian of the Southwest, Emmanuel LeRoy Ladurie, took the Montaillou Inquisition records as the testimonies of anthropological informants and mapped out the interrelations of the different households of the community. His book Montaillou: The Promised Land of Error is a very intimate and entertaining look at the medieval world.