In the mean time, Vandeleur's Brigade had been drawn up in support, on rather a commanding position, and Vivian approached it in the full expectation that it would open out for the passing through of his own men, and take the rearguard in its turn; but on the Hussars arriving within about 50 meters of the 4th Brigade, Vandeleur put it about, and retired — Vivian not being aware that Vandeleur had previously received orders to retire and leave the road clear for the retreat of the cavalry in his front Vivian immediately occupied the ground thus vacated, and, with a view to check the French advance more effectually, ordered the 18th Hussars to charge, as soon as the French approached within favourable reach.