|The walled town of Nördlingen in Bavaria|
The British Museum holds a manuscript which contains 58 letters written by Henry between 1332 and 1351; in fact, they are considered the earliest collection of personal letters written in German.
His life's goal—the only goal of which we know, based on the letters—was to guide and advise mystics, of which his mother was one. He wrote letters to, or visited, several mystics in order to encourage them. Among his correspondents were Christina Ebner, Margareta Ebner (no relation to Christina), Henry Suso, Johannes Tauler, and others.
He translated the memoirs of the 13th century mystic Mechthilde of Magdeburg, and used it as an example to other mystics to write their revelations. He also sent them books on theology, such as the works of Thomas Aquinas. His activities and letters shed a great deal of light on the thread of mysticism running through 14th century German religious society.
He was also a preacher in his own right; he was very popular, traveling to Avignon and Switzerland, where he was welcomed by the "Friends of God," a group inspired by the teachings of another German mystic, Meister Eckhart (c.1260 - 1328). He left them and preached in Alsace during the height of the Black Death there, then returned to Germany in 1350. His last known correspondence was with Christina Ebner in 1351; after that, we have no knowledge of the end of his life.