Martin Chemnitz (November 9, 1522 – April 8, 1586) was an eminent second-generation German Lutheran theologian, reformer, churchman, and confessor. In the Lutheran tradition he is known as Alter Martinus, the "Second Martin": Si Martinus non fuisset, Martinus vix stetisset ("If Martin [Chemnitz] had not come along, Martin [Luther] would hardly have survived") goes a common saying concerning him. He is commemorated as a pastor and confessor in the Lutheran Service Book of the Lutheran Church - Missouri Synod on November 9.
Chemnitz, born in Treuenbrietzen in Brandenburg to Paul and Euphemia Chemnitz, was the last of three children. His older siblings' names were Matthew and Ursula. His father was a successful merchant who died when Martin was eleven: thereafter, the family suffered from financial difficulties.
When he was old enough, Martin matriculated in Magdeburg. Upon completion of the course work, he became a weaver's apprentice. He helped his family with its clothing business for the next few years. When he was 20, he resumed his education at the University of Frankfurt (Oder). He remained in school until his finances were exhausted; he then took a teaching job in the town of Wriezen, supplementing his income by collecting the local sales tax on fish. His time at Frankfurt gave him the basic tools to continue his education on his own, researching areas in which he was interested and applying his naturally inquisitive mind to problems that others had worried over in the past.
In 1545 Chemnitz accompanied his cousin Georg Sabinus to school in Wittenberg (1545–47), where he studied under Martin Luther and Philipp Melanchthon. From Melanchthon he learned to shape his theological education, beginning with the difference between "law" and "gospel". In Chemnitz's words, though he heard Luther lecture often, he "did not pay Luther the attention he should have." (cf. Autobiography) Because of Luther's death and political events, Chemnitz transferred to the University of Königsberg (1547–48). Chemnitz graduated in the first class with a Master of Arts degree (1548). However, a plague soon infested the town of Königsberg, so Chemnitz left quickly for Saalfeld. When he judged it safe, Chemnitz returned to Königsberg in 1550, employed by Albert, Duke of Prussia, as the court librarian. In return for caring for the library and teaching a few courses as a tutor, he had unrestricted access to what was then considered one of the finest libraries in Europe.