Wilhelm Struve founded a dynasty of astronomers that lasted into the fifth generation. This book follows the fortunes of the first three generations: Wilhelm himself was an outstanding astronomer and geodesist, famous for his pioneering observations of double stars - observations whose quality had not been surpassed until the development of modern methods of instrumental observational analysis. He is also well known as one of the three men who - almost simultaneously - succeeded in measuring the distance to one of the fixed stars. He founded the great observatory of Pulkovo, just outside modern Leningrad, and was succeeded as Director of the institution by his son Otto, who forms the subject of the second part of the book. Otto, too, was a famous observer of double stars and a great practitioner of the fundamental astronomy of the nineteenth century.