Abstract: A cargo container (1) and a coupling assembly (13) for releasably coupling two or more of those containers (1) together in a side-by-side relationship. The assembly (13) has a male and female coupling part (14,15). The male coupling part (14) has a mounting structure (16) for mounting that part (14) on a container corner (12). A connecting element (25) is carried by the mounting structure (16) and retained for limited linear movement between a projected position projecting from the mounting structure (16) and a retracted position. The female coupling part (15) also has a mounting structure (31) for mounting that part (15) on an adjacent corner (12) of another container (1). That structure (31) provides a receiving recess (34) that can be aligned with the connecting element (25) so as to receive the element (25) when in the projected position.