This volume is a collection of the Nobel Lectures delivered by the prizewinners, together with their biographies, portraits and the presentation speeches for the period 1991 - 1995. Each Nobel Lecture is based on the work that won the prize. These volumes of inspiring lectures by outstanding physicists should be on the bookshelf of every keen student, teacher and professor of physics as well as of those in related fields.Below is a list of the prizewinners during the period 1991 - 1995 with a description of the works which won them their prizes.(1991) P-G de GENNES-for discovering that methods developed for studying order phenomena in simple systems can be generalized to more complex forms of matter, in particular to liquid crystals and polymers; (1992) G CHARPAK - for his invention and development of particle detectors, in particular the multiwire proportional chamber; (1993) R A HULSE & J-H TAYLOR JR. - for the discovery of a new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation; (1994) B N BROCKHOUSE -- for the development of neutron spectroscopy; C G SHULL -- for the development of the neutron diffraction technique; (1995) M L PERL -- for the discovery of the tau lepton; F REINES -- for the detection of the neutrino.