On March 11, 1801 came the announcement of the sudden death of Tsar Paul I, the son of Catherine the Great. The official cause of death was given as apoplexy, but the word murder soon was out and traveled far. Paul was succeeded by his son Alexander I. The results of Paul's rash, or possible mad, mistakes were quickly nullified. The war with England, which had throttled Russia's foreign trade, was brought to an end. An army of twenty thousand Don Cossacks, who had been sent toiling off across the desert steppes to conquer India, were recalled. Prussian troops were also recalled from Hanover. It had been the wish of the defunct Tsar that Hanover should be retained as a substitute for the territory Prussia was about to lose on the left bank of the Rhine.
In the fall of 1801 Tsar Alexander's sister Helena and her husband, a Prince of Schwerin returned to Berlin. They were commissioned to tell Frederick William that Alexander desired an interview with him at Memel. In June 1802 Fredrick William and Luise made the journey east to Memel. Luise was completely enchanted when she met the young Tsar. In her letters to her brother she wrote that Alexander is good, just and kind, and that she thought him worthy of affection. Luise, Frederick William and Alexander promised to keep in touch with one another. Alexander had come to Memel to promote an understanding between Russia and Prussia in regard to France. A watchful coexistence was his aim. This, he thought, would guarantee peace for the entire continent. The Tsar's sister Helena became very ill. She died in September 1803 in Paretz, and the heartfelt condolences exchanged between St.Petersburg and Berlin seemed one more bond between the Royal families of both countries.