Baltic Paganism has an unusual double character: it is both the genuinely late-surviving pre-Christian religion of the Lithuanians, Latvians and Old Prussians, and a modern reconstruction built from the fragments that survival left. The Baltic lands were the last corner of Europe to be Christianised, pagan Lithuania held out until its official conversion in 1387, and folk practice persisted for centuries after, so the raw material is deep: a vast body of folk songs (Lithuanian dainos, Latvian dainas), agrarian ritual, and the disapproving records of missionaries and church visitations. But there is no ancient scripture and no native mythography, so the "Baltic pantheon" of Perkunas, Dievas, Saule, Laima and the rest is assembled by scholars from these late and uneven sources. Recovering it means reading folk poetry, comparative Indo-European evidence and hostile clerical testimony together, and being honest about where reconstruction begins.