On the first night of the lying in state of the body of Queen Elizabeth II, the world got a chance to see just how tough a job royal guards have as they stand still keeping watch over the coffin.

Livestreaming footage showed one of the royal guards at Westminster Hall suddenly collapse.

The guard was standing at the foot of the late monarch’s casket when he suddenly fell to the floor.

The black-clad guard was holding a ceremonial staff when he appeared to faint, with nearby officials quickly rushing to his aid.

Other footage shows a rotation of the guard takes place in Westminster Hall where Queen Elizabeth II is Lying-in-State. These take place every 20 minutes.

Guards have 20 minutes on duty, and 40 minutes off duty.

Soldiers in ceremonial uniform are maintaining a constant 24-hour vigil around the Queen’s coffin while she is lying in state. The guards from units which include the Sovereign’s Bodyguard, the Household Division or Yeoman Warders of the Tower of London are required to remain completely still at the four corners of the catafalque.

While the soldiers rotate every 20 minutes, the hours of remaining completely still while standing are six hours in length. The incident happened on the first night of the Queen’s lying in state which gives members of the public the chance to pay their respects to the late monarch.

Massive queues of mourners have been winding through the streets of London to visit Westminster Hall ahead of the funeral next Monday (September 19).