The last great pagan country in Europe was the Grand Duchy of Lithuania, which began its rise under Gediminas in 1316. While the country had contact with Christians before and after this period, Grand Duke Jogalia's conversion to Christianity in order to marry Queen Jadwiga of Poland in 1377 and his rise to the Polish throne in 1387, officially converted the country to Catholicism. This was an attempt to stop the Teutonic Order's crusades against Lithuania and Poland and did not succeed until 1411 with the Peace of the Thorn.
Pagans in the SCA
Many SCAdians are pagans (some prefer the term Neo-Pagan) in their mundane lives. Symbolism such as a pentacle (a mullet of five points within a circle), a moon-and-pentacle emblem, assorted goddess-imagery, or a Thor's Hammer often mean the wearer is a modern pagan, whether or not their persona is.
In SCA heraldry for much of its history, a pentacle was not a permitted heraldic device although it is period. Some Pagans resented this restriction, but it was comparable to a similar ban on the Cross Calvary. Remember, overt religious displays of any variety are not allowed, but whatever you do in your tent is your business. However, this restriction was lifted in 2009, and the pentacle and pentagram are now permitted heraldic charges.
Owing to late Roman influence, Christianity was widespread throughout Europe and the Mediterranean before the medieval period. However, in more remote areas, such as Britain and Scandinavia it was either uncommon or had only thinly taken hold.
Norse personas, especially early in period would be pagan, as would Germanic ones. However, owing to Christian distrust of other religions, the social pressure from the ever-growing Christian community forced pagans to be regarded as the non-conformists.