Assembly for the mounting on an aircraft of a propulsion system having a vertical median plane, said assembly having: - a wing with a front spar, a suction-side panel fastened in the top part of said front spar and a pressure-side panel fastened in the bottom part of said front spar, wherein the front spar bears a first fitting at the vertical median plane, wherein said pressure-side panel bears two starboard-side and port-side second fittings at the bottom part of said front spar, and wherein the pressure side bears a third fitting positioned at the rear of said starboard-side and port-side second fittings, - an engine pylon having a primary structure, - a shackle fastened by a fifth connection to said third fitting of said pressure side, said fifth connection having at least one degree of freedom in rotation, - a first and a second rod (281a, 281b), wherein a first end of each first and second rod (281a, 281b) is fastened to the shackle respectively by a third and a fourth pivot connection, - a third rod, wherein a first end is fastened to the first fitting by a seventh connection, said seventh connection having at least one degree of freedom in rotation, and - a fastening base having a body as one with a rear part of the primary structure, said body having two starboard-side and port-side first fastening yokes extending to the rear and in the top part on the sides of said fastening base, each of said first fastening yokes being fastened to one of said second fittings (211b, 211b') by a first pivot connection, said body also having two starboard-side and port-side second fastening yokes extending to the rear and in the bottom part on the sides of said fastening base, each of said two second fastening yokes being fastened by a second connection to a second end respectively of the first and of the second rods (281a, 281b), said second connection having at least one degree of freedom in rotation, said body having at least one central third fastening yoke extending to the rear and at the vertical median plane, said third central fastening yoke being fastened to a second end of said third rod by a sixth connection, said sixth connection having at least one degree of freedom in rotation, the assembly having a starboard-side fourth fitting and a port-side fourth fitting, each of said fourth fittings being fastened to the primary structure of said engine pylon, for each fourth fitting, the assembly having a fourth rod of which a first end is fastened to said fourth fitting by an eighth pivot connection, said body also having two starboard-side and port-side fourth fastening yokes extending to the front and in the bottom part on the sides of said fastening base, each of said fourth fastening yokes being fastened to a second end of a fourth rod by a ninth pivot connection. - a wing with a front spar, a suction-side panel fastened in the top part of said front spar and a pressure-side panel fastened in the bottom part of said front spar, wherein the front spar bears a first fitting at the vertical median plane, wherein said pressure-side panel bears two starboard-side and port-side second fittings at the bottom part of said front spar, and wherein the pressure side bears a third fitting positioned at the rear of said starboard-side and port-side second fittings, - an engine pylon having a primary structure, - a shackle fastened by a fifth connection to said third fitting of said pressure side, said fifth connection having at least one degree of freedom in rotation, - a first and a second rod (281a, 281b), wherein a first end of each first and second rod (281a, 281b) is fastened to the shackle respectively by a third and a fourth pivot connection, - a third rod, wherein a first end is fastened to the first fitting by a seventh connection, said seventh connection having at least one degree of freedom in rotation, and - a fastening base having a body as one with a rear part of the primary structure, said body having two starboard-side and port-side first fastening yokes extending to the rear and in the top part on the sides of said fastening base, each of said first fastening yokes being fastened to one of said second fittings (211b, 211b') by a first pivot connection, said body also having two starboard-side and port-side second fastening yokes extending to the rear and in the bottom part on the sides of said fastening base, each of said two second fastening yokes being fastened by a second connection to a second end respectively of the first and of the second rods (281a, 281b), said second connection having at least one degree of freedom in rotation, said body having at least one central third fastening yoke extending to the rear and at the vertical median plane, said third central fastening yoke being fastened to a second end of said third rod by a sixth connection, said sixth connection having at least one degree of freedom in rotation, the assembly having a starboard-side fourth fitting and a port-side fourth fitting, each of said fourth fittings being fastened to the primary structure of said engine pylon, for each fourth fitting, the assembly having a fourth rod of which a first end is fastened to said fourth fitting by an eighth pivot connection, said body also having two starboard-side and port-side fourth fastening yokes extending to the front and in the bottom part on the sides of said fastening base, each of said fourth fastening yokes being fastened to a second end of a fourth rod by a ninth pivot connection.