The Laestadian revival movement takes its name from Lars Levi Laestadius (1800–1861), who served as a pastor in Swedish Lapland, first in Karesuando and later in Pajala, In January 1844 Laestadius met a believing Lapp woman, Milla Clemensdotter. This "Mary of Lapland" preached forgiveness to Laestadius, thereby helping him into living faith.
Laestadius began preaching forgiveness of sins in Karesuando church. A revival movement began in early spring of 1846, first among the Sami people, and then quickly spread to Finnish and Norwegian Lapland. Those who repented were concerned about the spiritual condition of their neighbors, and the ensuing discussions contributed to the spread of the movement. The revival movement brought about an overall change of life in many parishes. Drunkards repented, saloonkeepers closed their businesses, and court sessions ended.
One of the hallmarks of the Lappish revival movement were lay preachers, who began traveling more and more widely, having been either sent or called to preach in new areas. A few pastors of the state church also belonged to the movement from the beginning. Upon Laestadius’s death in 1861, his workmate, schoolmaster Juhani Raattamaa (1811–1899), became the new leading figure of the movement. The name Laestadianism began to be used in the 1870s, initially as a derogatory label. By the end of the 1800s Laestadianism had spread throughout most of the northern parts of Finland, Sweden, and Norway, as well as North America, Russia, and Estonia. By then there were already several hundred preachers.
Already in the 1870s doctrinal disputes appeared in Laestadianism. One of the main reasons for this was the fact that the movement had spread over a wide area without a cohesive organization. Nevertheless, Laestadianism remained outwardly united until the end of the century. At the turn of the century a so-called great schism took place in Laestadianism. At that time the movement split into Conservative Laestadianism, Firstborn Laestadianism, and New Awakening. The main reasons for the split were different understandings about justification, the significance of the Law for believers, and the essence of God’s congregation. Firstborn Laestadianism established a strong foothold in Sweden and Norway, while Conservative Laestadianism remained the main branch of Laestadianism in Finland. New Awakening was primarily a Finnish phenomenon. In America a Small Firstborn movement emerged between Conservative and Firstborn Laestadianism already at the end of the 1800s. Before long it became the largest Laestadian group in America. However, it functioned for a long time in cooperation with Conservative Laestadianism, and did not separate completely until the 1920s and 1930s.
Since the 1880s Conservative Laestadians in Finland have established associations called rauhanyhdistys (RY) for the purpose of organizing their activities. The name rauhanyhdistys (Association of Peace) refers above all to peace in the conscience of a believer. Organizing was linked to the movement becoming more established and its focus on domestic mission work. To organize mission work and coordinate the activities of the RYs, a central organization, Suomen Rauhanyhdistysten Keskusyhdistys (SRK), was established in 1914. Today there are 173 RYs in Finland. They have called nearly 900 lay preachers and over 100 pastors to function as their preachers.
Summer Services are the main annual event of Conservative Laestadianism. These services are arranged in late June and early July in different localities in Finland by turn. The first big services were arranged in 1906. Approximately 65,000–75,000 people attend the Summer Services each year. Nowadays the entire service program can be heard on the internet.
Conservative Laestadians in America have their own church, called Laestadian Lutheran Church (LLC). The central organization of Sweden’s Conservative Laestadians is Sveriges Fridsföreningarnas Centralorganisation (SFC).