Quantum Chromodynamics (QCD) was in its infancy when Gribov delivered his lectures on strong interactions. Since then QCD had been established as the true microscopic theory of hadrons.

The main (though not the only) focus of these lectures is to present the ‘old theory’ of hadron interactions (known as reggistics). This theory has realized the ‘Pomeranchuk—Gribov programme’ of describing strong interactions without appealing to the internal structure of hadrons. The old theory was launched in 1958 by the Pomeranchuk theorem and reached a climax in Gribov's prediction of an asymptotic equality of hadron cross sections 15 years later. With the advent of QCD, it was abandoned by the great majority of theorists in the mid-1970s and has been neither taught nor learnt since.

QCD — the ‘new theory’ — is now in its fourth decade. The QCD Lagrangian approach did marvels in describing rare processes. This is the realm of hard interactions that occur at small distances where quarks and gluons interact weakly due to the asymptotic freedom. The domain of expertise of the old theory is complementary: it is about normal size hadron—hadron cross sections, soft interactions that at high energies are dominated by peripheral collisions developing at large distances. QCD only starts to timidly approach this domain, with new generations of researchers borrowing (sometimes improperly) the notions and approaches developed by the ‘old theory’.