The French having advanced as far as Haarburg took up their position on the plateau of Schwartzenberg, which commands that little town and the considerable islands situated in that part of the river between Haarburg and Hamburg.  Being masters of this elevated point they began to threaten Hamburg and to attack Haarburg.  These attacks were directed by Vandamme, of all our generals the most redoubtable in conquered countries.  He was a native of Cassel, in Flanders, and had acquired a high reputation for severity.  At the very time when he was attacking Hamburg Napoleon said of him at Dresden, “If I were to lose Vandamme I know not what I would give to have him back again; but if I had two such generals I should be obliged to shoot one of them.”  It must be confessed that one was quite enough.

As soon as he arrived Vandamme sent to inform Tettenborn that if he did not immediately liberate the brother and brother-in-law of Morand, both of whom were his prisoners, he would burn Hamburg.  Tettenborn replied that if he resorted to that extremity he would hang them both on the top of St. Michael’s Tower, where he might have a view of them.  This energetic answer obliged Vandamme to restrain his fury, or at least to direct it to other objects.

Meanwhile the French forces daily augmented at Haarburg.  Vandamme, profiting by the negligence of the new Hanseatic troops, who had the defence of the great islands of the Elbe, attacked them one night in the month of May.  This happened to be the very night after the battle of Lutzsn, where both sides claimed the victory; and Te Deum was sung in the two hostile camps.  The advance of the French turned the balance of opinion in favour of Napoleon, who was in fact really the conqueror on a field of battle celebrated nearly two centuries before by the victory and death of Gustavus Adolphus.  The Cossacks of the Elbe could not sustain the shock of the French; Vandamme repulsed the troops who defended Wilhelmsburg, the largest of the two islands, and easily took possession of the smaller one, Fidden, of which the point nearest the right bank of the Elbe is not half a gunshot distant from Hamburg.  The 9th of May was a fatal day to the people of Hamburg; for it was then that Davoust, having formed his junction with Vandamme, appeared at the head of a corps of 40,000 men destined to reinforce Napoleon’s Grand Army.  Hamburg could not hold out against the considerable French force now assembled in its neighbourhood.  Tettenborn had, it is true, received a reinforcement of 800 Prussians and 2000, Swedes, but still what resistance could he offer to Davoust’s 40,000 men?  Tettenborn did not deceive himself as to the weakness of the allies on this point, or the inutility of attempting to defend the city.  He yielded to the entreaties of the inhabitants, who represented to him that further resistance must be attended by certain ruin.  He accordingly evacuated Hamburg on the 29th of May, taking with him his Hanseatic legions, which had not held out an hour in the islands of the Elbe, and accompanied by the Swedish Doctor Von Hess, whose imprudent advice was the chief cause of all the disasters to which the unfortunate city lied been exposed.