English: Arms of w:Frederick William, Duke of Brunswick-Wolfenbüttel (1771-1815), a German prince and Duke of Brunswick-Lüneburg and Oels. Nicknamed "The Black Duke", he was a military officer who led the Black Brunswickers against French domination in Germany. He briefly ruled the state of Brunswick-Wolfenbüttel from 1806 to 1807 and again from 1813 to 1815. Born in Braunschweig as the fourth son of Charles William Ferdinand, Duke of Brunswick-Lüneburg, and Princess Augusta of Great Britain. He was the cousin and brother-in-law (from 8 April 1795) of his friend George IV, Prince Regent of the United Kingdom (from 1811). Shield of the Duchy of Brunswick. Quarterly of 12:

• 1: Duchy of Lüneburg (Or semée of hearts gules, a lion rampant azure armed and langued of the second. The coat of arms of Lüneburg consisted of a blue lion on a gold field, which was sprinkled with red hearts. It was derived from the coat of arms of Denmark: the mother of Otto I, 1st Duke of Brunswick-Lüneburg was Princess Helena of Denmark. (Source: https://www.wikipe.wiki/wiki/nl/Wapens_van_Brunswijk_en_Lueneburg)
• 2: Duchy of Brunswick/Braunschweig (Gules, two lions passant guardant in pale or); In 1235 Otto I was elevated to Duke of Brunswick and Lüneburg by the Emperor. He was the only son of w:William of Winchester, Lord of Lunenburg, born in Winchester, England, the fifth and youngest son of the deposed Duke Henry the Lion of Saxony and Bavaria by his wife Matilda, the eldest daughter of King Henry II of England. Otto's royal lineage was accentuated by the arms designed for Brunswick and Lüneburg. The coat of arms of Brunswick consisted of two golden leopards in a red field and was derived from the coat of arms of England because of the marriage of Henry the Lion to Mathilde of England. (Source: https://www.wikipe.wiki/wiki/nl/Wapens_van_Brunswijk_en_Lueneburg)
• 3: County of Eberstein/Everstein (Azure, a lion rampant argent armed and langued gules crowned or); w:de:Everstein (Adelsgeschlecht); In 1425 w:Otto IV, Duke of Brunswick-Lüneburg (d.1446) (son of w:Bernard I, Duke of Brunswick-Lüneburg) married the heiress Countess Elizabeth of Eberstein (c.1415-1468), which gave him the possession of the County of Eberstein in 1408. The dukes included the arms of Eberstein and Homburg in their coat of arms in 1482. Their descendants, the later Electors of Hanover and the Dukes of Brunswick, continued to do so. (Source: https://www.wikipe.wiki/wiki/nl/Wapens_van_Brunswijk_en_Lueneburg)
• 4: lordship of Homburg; in 1409 w:Bernard I, Duke of Brunswick-Lüneburg (1358/64-1434) ("Middle House of Lüneburg") bought the lordship of Homburg, whose lords had died out in 1408. (Source: https://www.wikipe.wiki/wiki/nl/Wapens_van_Brunswijk_en_Lueneburg)
• 5: county of Diepholz. In 1585 the lords of Diepholz died out with Frederick II. The area later named a county fell to Duke William of Brunswick-Celle, (w:William the Younger, Duke of Brunswick-Lüneburg (d.1592)) the founder of the newer branch of Lüneburg. His brother Hendrik van Brunswijk-Dannenberg (w:Henry, Duke of Brunswick-Dannenberg (1533-1598))) was the founder of the newer branch Brunswijk. They both included Diepholz's coat of arms in their coat of arms.
• 6: county of Lauterberg;
• 7:
  • 7a: w:County of Hoya; w:de:Grafschaft Hoya; In 1582 the house of Hoya died out with Count Otto VIII. Half of the county of Hoya belonged to Duke Wilhelm of Brunswick-Celle (?w:William the Younger, Duke of Brunswick-Lüneburg (1535-1592)) from the middle branch of Lüneburg, the other half to Duke Julius of Brunswick-Wolfenbüttel from the middle branch of Brunswick. The coats of arms of the County of Hoya and the associated lordships of Alt-Bruchhausen and Neu-Bruchhauden were added to the arms of both branches. Brunswijk-Wolfenbüttel carried this coat of arms until 1596 and Brunswijk-Harburg until 1624. (Source: https://www.wikipe.wiki/wiki/nl/Wapens_van_Brunswijk_en_Lueneburg)
  • 7b1: lordship of Neu-Bruchhausen; Wappen der Grafschaft Neubruchhausen
  • 7b2: ; lordship of Alt-Bruchhausen;
• 8: county of Diepholz
• 9: county of Hohnstein; In 1593, the Klettenberg branch of the Counts of Hohnstein died out. The Counts of Stolberg inherited the county, but Brunswijk also claimed the county as liege lord. In 1596, the Dukes of Brunswick-Wolfenbüttel took up the arms in their coat of arms. Eventually the county was divided between Brunswijk and Stolberg. (Source: https://www.wikipe.wiki/wiki/nl/Wapens_van_Brunswijk_en_Lueneburg)
• 10: county of Regenstein;
• 11: county of Klettenberg;
• 12: county of Bankenburg. In 1599 the counts of Blankenburg died out with Count Johan Ernst. The county came to Brunswick-Wolfenbüttel as a vacant fief. The arms of the counts of Blankenburg were also added. After the death of Duke Hendrik Julius in 1613, the ranking was changed by his successor Frederik Ulrich. With this duke the middle house Brunswijk (in Wolfenbüttel) died out in 1634.(Source: https://www.wikipe.wiki/wiki/nl/Wapens_van_Brunswijk_en_Lueneburg)
  

More information see w:nl:Wapens van Brunswijk en Lüneburg[1]