In 1970, Brandenburg obtained his general higher education entrance qualification in Münster in Westphalia, did his substitute service from 1970 to 1972, and in 1972 began his studies in Romance languages and Slavic studies with a stay abroad at the Sorbonne . During this time he was also in the German Esperanto Youth active (Brandenburg speaks Esperanto as a mother tongue  ); From 1974 to 1975 he was its federal chairman. After the first philological state examination 1977 followed from 1978, the preparatory service for teaching at grammar schools, which he finished in 1980 with the 2nd State examination for teaching at grammar schools successfully.
In 1980 he entered the preparatory service for the Higher Foreign Service and in 1982 completed the career examination for the higher foreign service . From 1982 to 1984 he worked at the Embassy in Baghdad in Iraq and was from 1984 to 1986 Permanent Representative to the Consulate General in Leningrad in the Soviet Union . From 1986 to 1988 he worked at the Embassy in Moscow (Soviet Union) and from 1988 to 1991 at the Foreign Office in Berlin.