His father was a native of Altona, Hamburg, who emigrated in 1808 to avoid conscription in the Napoleonic armies, going first to Denmark and then Russia.

In 1835, the year of Karl's birth, he was asked by Tsar Nicholas I to supervise construction of the Pulkovo Observatory, of which he was director from 1839 to 1862.

From 1882 to 1892, a variety of powerful men and women passed through the Struves' door: the Theodore Roosevelt, Henry Brooks Adams, James G. Blaine, Leland Stanford, and many others.

In line with German practice, he was entitled to use the title of Baron von Struve while abroad, though this was denied him while resident in Germany or Russia.

Returning to St. Petersburg in 1892, Struve received his final diplomatic posting in 1893 when he was sent as Envoy Extraordinary and Minister Plenipotentiary to the Netherlands.