Assembly of a pylon and of a wing of an aircraft, the pylon comprising: - a primary structure that extends from front to rear along a longitudinal axis and that is in the form of a box with a rear face and an upper spar forming an upper face of the box, a longitudinal median plane separating the primary structure into two parts, left and right, the assembly comprising a front fastening system for fastening the pylon to the wing, which system is arranged on the upper face of the box halfway along the primary structure, a rear fastening system for fastening the pylon to the wing, which system is arranged at the rear of the primary structure, and an intermediate fastening system for fastening the pylon to the wing, which system is arranged on the upper face of the box between the front and rear fastening systems, characterized in that the rear fastening system comprises: - a pair of vertical shackles mounted so as to be articulated between the rear face of the primary structure and a first shoe fastened to the wing, wherein the shackles are fastened to the primary structure by a clevis-type connection with a pin (287a-b) oriented transversely with respect to the pylon, and - a pair of transverse shackles mounted so as to be articulated between the rear face of the primary structure and a second shoe fastened to the wing, wherein the shackles are fastened to the primary structure by a clevis-type connection with a pin (289a-b) oriented longitudinally with respect to the pylon. - a primary structure that extends from front to rear along a longitudinal axis and that is in the form of a box with a rear face and an upper spar forming an upper face of the box, a longitudinal median plane separating the primary structure into two parts, left and right, the assembly comprising a front fastening system for fastening the pylon to the wing, which system is arranged on the upper face of the box halfway along the primary structure, a rear fastening system for fastening the pylon to the wing, which system is arranged at the rear of the primary structure, and an intermediate fastening system for fastening the pylon to the wing, which system is arranged on the upper face of the box between the front and rear fastening systems, characterized in that the rear fastening system comprises: - a pair of vertical shackles mounted so as to be articulated between the rear face of the primary structure and a first shoe fastened to the wing, wherein the shackles are fastened to the primary structure by a clevis-type connection with a pin (287a-b) oriented transversely with respect to the pylon, and - a pair of transverse shackles mounted so as to be articulated between the rear face of the primary structure and a second shoe fastened to the wing, wherein the shackles are fastened to the primary structure by a clevis-type connection with a pin (289a-b) oriented longitudinally with respect to the pylon. - a pair of vertical shackles mounted so as to be articulated between the rear face of the primary structure and a first shoe fastened to the wing, wherein the shackles are fastened to the primary structure by a clevis-type connection with a pin (287a-b) oriented transversely with respect to the pylon, and - a pair of transverse shackles mounted so as to be articulated between the rear face of the primary structure and a second shoe fastened to the wing, wherein the shackles are fastened to the primary structure by a clevis-type connection with a pin (289a-b) oriented longitudinally with respect to the pylon.