Who was who in Lortzing's life?

Blum, Robert  (1807-1848)
Secretaire of the City theatre in Leipzig from 1832 unto 1847. He wrote in several important magazines and was a member of the Schiller-Verein in Leipzig. On 9-11-1848 he was by summary justice sentenced to death by the counter revolution and shot dead at the Brigittenau in Vienna. He wrote the libretto of "Die Schatzkammer des Ynka", Lortzing's only tragic opera.
Düringer, Philipp Jacob (1809 - 1870). 
Close friend of Lortzing and his first biographer (_Albert Lortzing, sein Leben und Wirken_, Leipzig 1851). He studied medicine, but became an actor. It is suggested that they already met in Coburg, but Düringer was then only four years old. However: their friendship dates from the period in Leipzig, where Düringer worked from 1835. He also wrote lyrics for some of the songs in Lortzing's operas. His wife, the mezzo-soprano Caroline Düringer - de Lange, was the first countess in "Der Wildschütz". In 1843 he became stage manager in Mannheim. 
Glaßbrenner, Adolf (1810 - 1876)

Gollmick, Karl. (1796 - 1866).
Studied theology and music. After teaching French in Frankfurt, he wrote several opera libretti and some articles for magazines. Gollmick met Lortzing in Strasbourg, and they remained friends for the rest of their lives, even though Lortzing rejected his proposal to put Gollmick's "Donna Anna" and  "Floris von Namur" to music. Lortzing's letters to Gollmick (30-11-1843 and 08-07-1845) are important examples of Lortzing expressing himself on the aesthetics of opera.
Litho by Wallerstein
Grabbe, Christian Dietrich (1801 - 1836)
Drawing by Theodor Hildebrandt, 1832
Herloßsohn, Karl Borromäus Sebastian (1802 - 1849)
Kotzebue, August von (1761 - 1819)
Laube, Heinrich. (1806 - 1884).
Lichtenstein, Freiherr Carl August von
(8-9-1767 - 10-9-1845)

Nestroy, Johann Nepomuk (1801 - 1862)

Reger, Philipp Salomon. (1804 - 1857). 
One of the closest friends of Lortzing. Wrote the libretto of Hans Sachs.
Ringelhardt, Friedrich Sebald (1785 - 1855)

Röckel, August (1814 - 1876)

Rungenhagen, Karl Friedrich (1778 - 1851). Lortzing's teacher.
Schmidt, Karl Christian. (1793 - 1855).