In OTL, the eponymous saying refers to the situation in Sweden in 1808-09, when, during the Napoleonic Wars, Sweden had lost Finland to Russia and tried to conquer Norway in compensation for lands lost.
Under Russian pressure Denmark declared war on Sweden in 1808. Russia moved into Finland and Sweden tried to take Trondheims Len in central Norway. Field Marshall Duke Christian August, regent of Norway, led the successful defence and repulsed the Swedish assault. Marshall Bernadotte was to land in Sweden with a French army of 26000 - a large part of which were Spanish troops. When Napoleon occupied Spain, the Royal Navy transported 9000 Spanish troops from Nyborg in Funen to Spain. In 1809, the last of Napoleon's troops left Denmark.
The Swedish invasion army negotiated a settlement in Norway and then marched on Stockholm, toppling mad King Gustav IV. Offered the throne, Frederick VI. rejected it on the grounds of the Swedish coupmakers being insurgents. Gustav’s uncle Karl XIII. was elected King but being without offspring a heir was needed and Duke Christian August was then approached and at the peace negotiations in Jönköping on December 10., 1809, Frederick VI. allowed Christian August to accept the offer. The Swedish hope was that Christian August would be willing to incorporate Norway into Sweden as a compensation for the loss of Finland. This was rejected by Christian August.
Christian August died in 1810 of a heartattack and Frederick VI. was once again brought up as successor but Sweden wants Christian August’s brother, Frederick Christian, who was blockaded in his home by Frederick VI. because of fears of having the age old strife of Sleswig-Holstein versus Denmark reinvigorated. The Swedes then went for an approval of Frederick Christian by Napoleon, but ended up with Bernadotte.
POD: But WI Frederick 6 had accepted the Swedish proposal ? Read the TL and find out !