Latvian language
The Middle dialect is spoken in central and Southwestern Latvia. Kursenieki language, which used to be spoken along Curonian Spit, is closely related to the varieties of middle dialect spoken in Courland. The dialect is divided into the Vidzeme variety, the Curonian variety and the Semigallian variety. The Vidzeme variety and the Semigallian variety are closer to each other than to the Curonian variety, which is more archaic than the other two. There are three intonations in the Middle dialect. In the Semigallian variety, "ŗ" is still used. Standard Latvian is based on the middle dialect.
Latvia
Several important cultural changes occurred during this time. Under Swedish and largely German rule, western Latvia adopted Lutheranism as its main religion. The ancient tribes of the Couronians, Semigallians, Selonians, Livs, and northern Latgallians assimilated to form the Latvian people, speaking one Latvian language. Throughout all the centuries, however, an actual Latvian state had not been established, so the borders and definitions of who exactly fell within that group are largely subjective. Meanwhile, largely isolated from the rest of Latvia, southern Latgallians adopted Catholicism under Polish/Jesuit influence. The native dialect remained distinct, although it acquired many Polish and Russian loanwords.