18. Russian Armies marched across the frozen sea during several wars
For over three centuries before the American Revolution, Sweden and Russia (called Muscovy in the early wars) fought a series of conflicts for sovereignty over the region of the Baltic. Denmark and Poland frequently allied themselves with the Russians, while Sweden received support from what became Great Britain, the Ottoman Empire, and others. The allied nations changed sides frequently, depending upon the causes of each individual conflict and its impact on their own political and territorial ambitions at the time. The bulk of the wars took place during the period of history known as the Little Ice Age. During the Little Ice Age winters were longer, colder, and featured more precipitation than the norm.
Several times during the wars between the Swedes, Russians, and their various allies, Russian Armies marched across bodies of water which froze solid during the winter months, taking with them their baggage, wagons, and heavy artillery pieces. The Gulf of Bothnia and the Gulf of Finland were both used as open plains by the Russian Armies, which marched across them and attacked targets presumed safe by the Swedes. The last time the Russians crossed frozen seas on foot was during the Finnish War in 1809, an adjunct of the Napoleonic Wars.
