A suitcase comprising: · a bag; · at least two trolleys (11, 12), each trolley comprising a casing (102, 202), at least one wheel (101, 201), each wheel including a hub, and means for mounting the wheel (101, 201) to rotate relative to the casing (102, 202); · means (110, 210) for mounting the two casings in co-operation with the bag; · a handle; · means for mounting said handle in co-operation with the bag in such a manner that it is suitable for taking up at least two positions, a first position in which it is close to the bag, and a second position in which it is further away from the bag than when it is in its first position; · means for blocking/unblocking the wheel of each trolley, said blocking/unblocking means comprising at least a first control element (103, 203) and being arranged in such a manner as to be suitable for taking up two states, respectively a blocking state and an unblocking state, the blocking state being a stable state, the transition from the blocking state to the unblocking state being obtained by applying a traction force on said first control element (103, 203), said blocking/unblocking means further including a second control element (104, 204) secured to the hub of the wheel, the first and second control elements (103, 203; 104, 204) being suitable for co-operating together in two relative positions, a first position in which they are coupled together to block rotation of the hub of the wheel (101, 201), and a second position in which they are uncoupled to allow the hub of the wheel (101, 201) to rotate freely relative to the casing of the wheel (102, 202); · means for subjecting said first control element (103, 203) to a resilient force tending to put the first and second control elements into their first position; · controllable means for generating said traction force, mounted in co-operation with said handle; and · means for transmitting said traction force to said first control element (103, 203) of each wheel (101, 201); said second control element (104, 204) being constituted by a plurality of grooves (105, 205) formed in the hub of the wheel (101, 201), and the suitcase being characterized by the fact that: said first control element (103, 203) is constituted by a lever (106, 206) and a stud (107, 207) secured to said lever (106, 206), said stud being arranged on said lever in such a manner that when the first and second control elements (103, 203; 104, 204) are in their first position, said stud is suitable for plunging into said groove. · a bag; · at least two trolleys (11, 12), each trolley comprising a casing (102, 202), at least one wheel (101, 201), each wheel including a hub, and means for mounting the wheel (101, 201) to rotate relative to the casing (102, 202); · means (110, 210) for mounting the two casings in co-operation with the bag; · a handle; · means for mounting said handle in co-operation with the bag in such a manner that it is suitable for taking up at least two positions, a first position in which it is close to the bag, and a second position in which it is further away from the bag than when it is in its first position; · means for blocking/unblocking the wheel of each trolley, said blocking/unblocking means comprising at least a first control element (103, 203) and being arranged in such a manner as to be suitable for taking up two states, respectively a blocking state and an unblocking state, the blocking state being a stable state, the transition from the blocking state to the unblocking state being obtained by applying a traction force on said first control element (103, 203), said blocking/unblocking means further including a second control element (104, 204) secured to the hub of the wheel, the first and second control elements (103, 203; 104, 204) being suitable for co-operating together in two relative positions, a first position in which they are coupled together to block rotation of the hub of the wheel (101, 201), and a second position in which they are uncoupled to allow the hub of the wheel (101, 201) to rotate freely relative to the casing of the wheel (102, 202); · means for subjecting said first control element (103, 203) to a resilient force tending to put the first and second control elements into their first position; · controllable means for generating said traction force, mounted in co-operation with said handle; and · means for transmitting said traction force to said first control element (103, 203) of each wheel (101, 201); said first control element (103, 203) is constituted by a lever (106, 206) and a stud (107, 207) secured to said lever (106, 206), said stud being arranged on said lever in such a manner that when the first and second control elements (103, 203; 104, 204) are in their first position, said stud is suitable for plunging into said groove.