Date of Birth: 10/22/1704
Descendant of the famous Brevern in Riga from the 17th century. In 1694 Brevern received a title of nobility of the Kingdom of Sweden, and since then constantly being born Brevern in Estland (1745), Livonia (1747) and Kurland (1833) matriculation. 
Karl von Brevern began his diplomatic career in 1726 secretary to the embassy in Sweden, later secretary and translator in the College of Foreign Affairs.
In the years 1731-1734 as the Secretary of Ministry of Foreign Affairs went on errands to Vienna, Dresden and Berlin.
In 1735 he was appointed secretary of the office and served as a link between Osterman and Biron.
From 24 April 1740 to 15 April 1741 was president of the St. Petersburg Academy of Sciences.  In this position was Carl von Brevern reports to the Empress Anna Ivanovna par with cabinet ministers. 
He was implicated in a case of regency Biron and after the fall of Biron lost his influence at court and the president of the Academy of Sciences. On accession to the throne of Elizabeth I regained influence and was appointed Minister of the conference.
Since 1742, together with Chancellor Count Alexei Petrovich Bestuzhev-Ryumin led the College of Foreign Affairs. However Bestuzhev Brevern belonged to the so-called "Austrian-British party" at the Russian court.
At the direction of Brevern the College of Foreign Affairs was invited to the Academy of Sciences of the Goldbach, who exercised censorship of correspondence, allowing the board to be aware of all the courtiers and international affairs. With the participation of Russian Brevern was deleted Marquis Chetardy, which led to a weakening of the so-called "Franco-Prussian party" at the Russian court. In the midst of these developments, Karl von Brevern died, as they thought of the poison. 
Karl von Brevern Russia signed a treaty with England (1741) and Prussia (1743).