Jacob Israelachvili was awarded 1st class in parts I and II of the Natural Sciences Tripos at Cambridge (1965-71). He obtained his PhD under the supervision of Professor David Tabor, the first recipient of the Tribology Gold Medal. Appointments followed at the University of Stockholm and at the Australian National University, after which in 1986 he settled at the University of California, Santa Barbara. As early as in Cambridge, Professor Israelachvili declared his interest in the molecular forces in biological and complex materials systems. He pioneered the use of the Surface Forces Apparatus (SFA) in the measurement of surface forces. Developing and applying this novel approach Professor Israelachvili, over the next two decades, at Cambridge, Canberra and Santa Barbara, laid the basis of our current understanding of the of the contribution of van der Waals and other forces to adhesion, friction, lubrication, and more generally to the structure and properties of liquid films confined between solid surfaces. He discovered and explained the important molecular ordering that occurs in very thin liquid films confined between smooth surfaces, and the consequent changes that occur in the physical properties of thin films as the surfaces are brought together or sheared past each other. His work now underpins much of our understanding of interfacial lubrication and friction. In recent years Prof Israelachvili has gone further, to apply the SFA and other new experimental techniques in areas such as electro-rheological fluids, polymer films, biological membranes and electro-chemistry. At the NATO institute on “Fundamentals of Friction”, Braunlage, Germany, August 1991, he explained ground-breaking studies showing that stick-slip of atomically-thin lubricant films were also due to dynamic and time-dependent molecular rearrangements. Studies which led to a new understanding of the origins of Amontons’ Law at the molecular level demonstrated how friction and adhesion were thermodynamically determined through the irreversible compression-decompression cycles of trapped molecules. Professor Israelachvili is a world leader in the area of measurements and understanding of surface forces and their relevance to tribology. In particular, his development of the technique to measure normal and frictional forces between various (including inorganic, organic and biological) surfaces across liquids and boundary lubricants down to the nm and ångstrom level using sophisticated attachments to the SFA has led to major advances in the related area of adhesion and tribology over the past four decades. His book ‘Intermolecular and surface forces’ was an innovative text when it first appeared in 1985, in bringing together for the first time a comprehensive and integrated description of the different forces (such as van der Waals forces, electrostatic double layer interactions, forces arising from molecular structure, and others) that act between molecules and surfaces across liquids. The book, now a text book in its third edition, has indeed become a classic and a major reference work for understanding the molecular origins of tribological processes. As well as his text book, he has to his name more than 400 published papers and articles. A world leader in the area of measurements and understanding of surfaces forces and their relevance to tribology, his work has led to major advances in the area of tribology. Recognised as a most outstanding and influential tribologist, Professor Israelachvili is a worthy recipient of the world’s highest honour in tribology – the 2013 Tribology Gold Medal.