The Baltic peoples were the last in Europe to be Christianised, and that late date is the reason there is any pantheon to describe. Lithuania converted formally at the end of the fourteenth century, which means the crusading chronicles were describing a functioning pagan religion rather than reconstructing a vanished one.
What they describe is thinly structured. Dievas is the sky god, and the name is itself the inherited Indo-European word for god, which argues for antiquity. Perkunas, the thunderer, dominates the later folk material by a wide margin, and which of the two headed the pre-Christian cult is genuinely disputed. Below them, a scatter of figures attached to the sun, the moon, the earth, fate, fire and the household, several of them known chiefly from lists compiled by churchmen.
The strongest impression the material gives is of a religion of place and household rather than of temple and priesthood. Sacred groves, particular trees, stones, springs and a fire kept burning recur constantly in the sources, and it is the destruction of these that the chronicles record.
The sanctuary called Romuva, named by Peter of Dusburg as the seat of a chief priest, has never been located and its existence as described is doubted.
The tradition did not simply stop. Folk practice persisted alongside Christianity for centuries, and Romuva today is a recognised religious community in Lithuania.