When Gustavus was blockaded in Nuremberg by Wallenstein Franz Albert left the camp of the latter and presented himself in that of Gustavus as a convert to the Reformed Religion and anxious to serve as a volunteer under him.  No quarrel or disagreement had, so far as is known, taken place between him and Wallenstein, nor has any explanation ever been given for such an extraordinary change of sides, made, too, at a moment when it seemed that Gustavus was in a position almost desperate.  By his profession of religious zeal he managed to win the king’s heart, but Oxenstiern, when he saw him, entertained a profound distrust of him, and even warned the king against putting confidence in this sudden convert.

Gustavus, however, naturally frank and open in disposition, could not believe that treachery was intended, and continued to treat him with kindness.  After the assault made by Gustavus upon Wallenstein’s position Franz Albert quitted his camp, saying that he was desirous of raising some troops for his service in his father’s territory.  He rejoined him, however, with only his personal followers, on the very day before the battle of Lutzen, and was received by Gustavus with great cordiality, although the absence of his retainers increased the general doubts as to his sincerity.

He was by the king’s side when Gustavus received his first wound.  He was riding close behind him when the king received his second and fatal wound in the back, and the moment the king had fallen he rode away from the field, and it is asserted that it was he who brought the news of the king’s death to Wallenstein.

Very soon after the battle he exchanged the Swedish service for the Saxon, and some eighteen months later he re-embraced the Roman Catholic faith and re-entered the Imperial army.

A stronger case of circumstantial evidence could hardly be put together, and it would certainly seem as if Lauenburg had entered the Swedish service with the intention of murdering the king.  That he did not carry out his purpose during the attack on the Altenburg was perhaps due to the fact that Gustavus may not have been in such a position as to afford him an opportunity of doing so with safety to himself.

It is certainly curious that after that fight he should have absented himself, and only rejoined on the eve of the battle of Lutzen.  The only piece of evidence in his favour is that of Truchsess, a chamberlain of the king, who, affirmed that he saw the fatal shot fired at a distance of ten paces from the king by an Imperial officer, Lieutenant General Falkenberg, who at once turned and fled, but was pursued and cut down by Luckau, master of horse of Franz Albert.

The general opinion of contemporary writers is certainly to the effect that the King of Sweden was murdered by Franz Albert; but the absolute facts must ever remain in doubt.

On the morning after the battle Wallenstein, having been joined by Pappenheim’s infantry, sent a division of Croats back to the battlefield to take possession of it should they find that the Swedes had retired; but on their report that they still held the ground he retired at once from Leipzig, and, evacuating Saxony, marched into Bohemia, leaving the Swedes free to accomplish their junction with the army of the Elector, thus gaining the object for which they had fought at Lutzen.