A quick look at Lares: The Roman household guardian spirits
The example used above dates to the early 1st century AD, and is currently located at the National Archaeological Museum of Spain (photo taken by Luis García).
It was believed that the lares observed, influenced, and protected all that happened within the boundaries of their placement and function. The presence of their statues seem to have been required at all important family events.
Lares were Roman guardian spirits, possibly the ghosts of ancestors. They were worshipped as the protecting spirits of crossroads, in the city as guardians of the state, and most importantly as protectors of the house and its inhabitants. Lares had no clear personalities or mythologies associated with them.
Nearly every Roman household possessed statuettes of the lares, usually in pairs that were placed in a lararium, or shrine, that was built in the central court (atrium) of the home or in the kitchen. These shrines sometimes contained paintings rather than statuettes of the deities. Offerings, sacrifices, and prayers were made to the lares and to other household gods (the penates, the guardians of the cupboard, for example). The lares of the crossroads, associated with the emperor’s household gods beginning in the era of Augustus, were worshipped publicly.
-Roman Art: A Resource for Educators, page 97.
The following are examples of larariums, the household shrines which contained the lares statuettes or paintings.
1. This example is from the Amorini Dorati (House of Golden Cupids), Pompeii. Household lares statuettes would have once been placed within. (source, photo by Paul Asman and Jill Lenoble)
2. Here’s an example of an alternate form of lararium, with painted lares instead of the statuettes. House of the Vettii, Pompeii. (source)