From the LCMS website:
Philipp Nicolai (1556–1608) was a pastor in Germany during the Great Plague, which took the lives of 1,300 of his parishioners during a sixth-month period. In addition to his heroic pastoral ministry during that time of stress and sorrow, he wrote the texts for “Wake, Awake, for Night Is Flying” and “O Morning Star, How Fair and Bright,” known, respectively, as the king and queen of the Lutheran chorales. Johann Heermann (1585–1647), also a German pastor, suffered from poor health as well as from the ravages of the Thirty Years’ War (1618–1648). His hymn texts are noted for their tenderness and depth of feeling. Paul Gerhardt (1607–1676) was another Lutheran pastor who endured the horrors of the Thirty Years’ War. By 1668 he lost his pastoral position in Berlin (for refusing to compromise his Lutheran convictions), and endured the death of four of his five children and his wife. He nevertheless managed to write 133 hymns, all of which reflect his firm faith. Along with Martin Luther he is regarded as one of Lutheranism’s finest hymn writers.