Estonian is an Finno-Ugric language closely related to Finnish spoken by about 1.1 million people in Estonia. The main difference between Estonian and Finnish is that Finnish has a lot of loan words from Swedish, while Estonian contains many words of German origin, plus some words from Russian, Latin, Greek and English. There is considerable mutual intelligibility between Estonian and Finnish.
The oldest examples of written Estonian are names, words, and phrases found in early 13th century chronicles. The earliest surviving longer text dates from the 16th century. An Estonian textbook first appeared in 1637. Ferdinand Johann Wiedemann published the comprehensive Estonian-German dictionary in 1869, and a grammar describing the Estonian language in 1875.
source
wikipedia.org,
omniglot.com,
evertype.com &
ethnologue.com