This paper presents the experimental and analytical validation of the lateral strength of dry block masonry walls under in-plane loading. The analytical evaluation of the in-plane frictional resistances activated at the onset of the rocking-sliding mechanisms is revisited in order to account for the different contributions of the self weight of the wall and additional loads. It is assumed that the wall is arranged in a running bond pattern, with rigid blocks and dry contact interfaces governed by cohesionless Coulomb failure criterion. The accuracy and robustness of the analytical results are assessed by experimentally testing both the resultant frictional resistances and their applications points. Both pure sliding and rocking-sliding fail...