Roman religion did not live only in temples. Every household kept its own cult, and the lararium was its furniture: a shrine to the Lares familiares, the twinned dancing guardians of the family and its place; the Penates, protectors of the store cupboard whose name comes from the inner part of the house; and the genius, the generative spirit of the head of the household, often painted between the Lares with veiled head and offering dish.
Offerings were small and constant. Portions of the meal, spelt cakes, incense, wine and garlands were given at the shrine, with particular attention on the Kalends, Nones and Ides of each month and at the family's thresholds: a bride's first entry into the house, a son's coming of age, when the bulla worn in childhood was dedicated to the Lares, a safe return from a journey. Slaves and freedmen took part in the household cult, and the festival of the Lares of the crossroads, the Compitalia, carried the same devotion out into the neighborhood shrines where properties met.
Writers from Cato to Ovid attest the cult's ordinariness; it needed no priest beyond the head of the household. That domestic constancy is why historians treat the lararium as the layer of Roman religion that persisted longest and mattered most to most people, whatever happened in the great public temples of the state.