A fence post assembly (120, 420, 440) comprising: a fence post being in the form of a picket and having an arm; and at least one keeper for holding a fencing member relative to the post, wherein the at least one keeper comprises: a slot (123, 444) extending within the fence post arm for receiving the fencing member; wherein the slot (123, 444) is substantially L-shaped and has an open end and a blind end; and a retainer assembly connected to the fence post, wherein the retainer assembly comprises a pivot pin and a retainer (124, 448), wherein the retainer (124, 448) is pivotable relative to the fence post arm between a holding position in which the fencing member is holdable relative to the fence post and a release position in which the fencing member is releaseable from the fence post, wherein the retainer (124, 448) comprises: a post mounting region at which the retainer (124, 448) is mounted to the arm by way of the pivot pin; a fencing member engaging region (127, 147, 247); and a counter-balance region (130, 150, 250) for biasing the retainer (124, 448) by way of gravity to pivot to the holding position, characterized in that in the holding position the fencing member engaging region (127, 147, 247) extends across the slot (123, 444) at a point in substantially vertical alignment with the pivot pin so as to obstruct movement of the fencing member from the blind end towards the open end of the slot (123, 444). a fence post being in the form of a picket and having an arm; and at least one keeper for holding a fencing member relative to the post, wherein the at least one keeper comprises: a slot (123, 444) extending within the fence post arm for receiving the fencing member; wherein the slot (123, 444) is substantially L-shaped and has an open end and a blind end; and a retainer assembly connected to the fence post, wherein the retainer assembly comprises a pivot pin and a retainer (124, 448), wherein the retainer (124, 448) is pivotable relative to the fence post arm between a holding position in which the fencing member is holdable relative to the fence post and a release position in which the fencing member is releaseable from the fence post, wherein the retainer (124, 448) comprises: a post mounting region at which the retainer (124, 448) is mounted to the arm by way of the pivot pin; a fencing member engaging region (127, 147, 247); and a counter-balance region (130, 150, 250) for biasing the retainer (124, 448) by way of gravity to pivot to the holding position, characterized in that in the holding position the fencing member engaging region (127, 147, 247) extends across the slot (123, 444) at a point in substantially vertical alignment with the pivot pin so as to obstruct movement of the fencing member from the blind end towards the open end of the slot (123, 444). a slot (123, 444) extending within the fence post arm for receiving the fencing member; wherein the slot (123, 444) is substantially L-shaped and has an open end and a blind end; and a retainer assembly connected to the fence post, wherein the retainer assembly comprises a pivot pin and a retainer (124, 448), wherein the retainer (124, 448) is pivotable relative to the fence post arm between a holding position in which the fencing member is holdable relative to the fence post and a release position in which the fencing member is releaseable from the fence post, wherein the retainer (124, 448) comprises: a post mounting region at which the retainer (124, 448) is mounted to the arm by way of the pivot pin; a fencing member engaging region (127, 147, 247); and a counter-balance region (130, 150, 250) for biasing the retainer (124, 448) by way of gravity to pivot to the holding position, characterized in that in the holding position the fencing member engaging region (127, 147, 247) extends across the slot (123, 444) at a point in substantially vertical alignment with the pivot pin so as to obstruct movement of the fencing member from the blind end towards the open end of the slot (123, 444). a post mounting region at which the retainer (124, 448) is mounted to the arm by way of the pivot pin; a fencing member engaging region (127, 147, 247); and a counter-balance region (130, 150, 250) for biasing the retainer (124, 448) by way of gravity to pivot to the holding position, characterized in that in the holding position the fencing member engaging region (127, 147, 247) extends across the slot (123, 444) at a point in substantially vertical alignment with the pivot pin so as to obstruct movement of the fencing member from the blind end towards the open end of the slot (123, 444).