Friedrich Wilhelm Rembert von Berg

The Sagnitz castle, where Count von Berg and his siblings spent their childhood in

Friedrich Wilhelm Rembert von Berg was born on May 15, 1794 (26 according to the Julian calendar in use in Russia at the time), in the family estate in the small village of Sagnitz, in the Kreis Dorpat of the Governorate of Livonia. His father Friedrich Georg von Berg (1763–1811) was a state councillor and his mother Gertruda Wilhelmine von Ermes (1774–1844) was a young noblewoman, the younger Friedrich was the first cousin once removed[lower-alpha 2] of generals Gregor (1765–1838) and Burchard Magnus von Berg (1764–1838), both of whom served in the Russian Imperial Army during the course of the Napoleonic Wars. Genealogists still debate[8] where the Livonian noble Berg family originated in, many speculated they originated in Westphalia. The first known ancestor of the family to appear in Livonia was Otto von Berg. His son, who was also named Otto, was a vassal of the Livonian Knighthood.

Friedrich belonged to the Sagnitz branch of the Luist line of the family. The Luist line[6] was formed by Captain Gustav von Berg (1656–1715), and the further divided Sagnitz branch[7] was formed by Friedrich's grandfather Major Gotthard Ernst von Berg (1714–1766).

Berg along with his siblings spent their childhood in the Sagnitz castle and were home educated by the young Friedrich Georg Wilhelm Struve.[9] He was brought up as a Lutheran.[10] After he finished his home education he studied in the Tartu Gymnasium in Dorpat. Originally not seeking a military career as a family tradition, Berg enrolled into the Philosophy faculty of Imperial University of Dorpat in 1810.[11] But after Napoleon invaded of Russia in 1812, Berg dropped out from university and voluntarily entered the Russian Imperial Army. He entered the army as a Fahnenjunker and was enlisted into the 6th Libau Infantry Regiment which was stationed at the north-western part of Russia to defend against Napoleon. Berg's bravery during the war of 1812 rewarded him the rank of lieutenant from Alexander I personally. He was also appointed second to the quartermaster due to his high education and being multilingual among Russian soldiers at the time.

After Napoleon was pushed out of Russia, Berg was transferred to a partisan unit under the commands of Baron von Tettenborn and Pavel Kutuzov and took part in actions in Germany including the Battle of Leipzig.

Berg was born the eldest son of a family with three siblings, including his younger brother Gustav "Astaf" Gotthard Karl von Berg, owner of the Alt-Ottenhof Manor.[11] His other brother Alexander was a diplomat and consul in Naples and London.[11] Count von Berg married late in his life. In 1839, after a long relationship with the Baroness de Sassè, he married[11] a rich Milanese aristocrat Leopoldina Cicogna-Mozzoni (1786–1874), the widow of the Italian politician Alessandro Annoni, with whom he had no children. However, after his brother Gustav's death in 1861, Friedrich adopted his orphaned nephews and brought them under his care:

• Friedrich Georg Magnus Graf von Berg (1845–1938)
• Alexander Rembert Joachim Graf von Berg (1847–1893)
• Georg Erich Rembert Graf von Berg (1849–1920)
• Emilie Wilhelmine "Minni" Anna Marie Ulrike Pauline Gräfin von Berg (1852–1945)

Since his marriage was childless, his Austrian and Finnish comital titles were inherited by his nephews/adoptive children.