As Big Ben chimed 6am the gun carriage, drawn by six horses from the King's Troop of the Royal Horse Artillery, left the Queen's Chapel at St James's Palace. To the sounds of the funeral march, and a muffled drum, detachments of the Army, Navy and Air Force marched slowly into The Mall where Grenadier Guardsmen lined the route through Horse Guards into Whitehall and into Westminster Hall where the Queen Mother will lie in state from tomorrow afternoon until Monday.