Before the translation, two comments.
Note 1 (source)
Already during the Northern War [Russia vs. Sweden, 1700—1721] a Russian corps under Apraksin’s command made a 130-km ice march from the island of Cotlin to the Finnish coast in order to lay siege to Viborg. The Russian army made a major march across the frozen Bothnian bay during the Russo-Swedish war of 1808—1809. The march took place in February and early March of 1809 in three different directions.
The first corps, commanded by Bagration, first got across from Åbo to the Kumling island, then to the island of Åland. From there, the corps’ vanguard under general Kulnev’s command crossed the Ålandshaf strait and marched onto the Swedish shore. Total distance covered was 400 km. The second corps, led by Barclay de Tolly, started out of the Finnish town of Vaasa, marched across the frozen Bay of Bothnia in the Kvarken area (around 70 km in total) and walked ashore in Sweden, around Umeå. During the march of the third corps under Shuvalov’s command by land from Uleåborg to Torneå, then to Kalix, General Alexeyev’s troops marched on the ice of the Bothnian Bay in order to circumvent the Swedish army’s right flank.
Note 2. Shvarts’ own comment, which doesn’t seem historically correct.
The dispute between the Russians and the Swedes over the possession of Finland was resolved instantly when a small Russian army, having crossed the Bay of Bothnia covered with melting ice, appeared in sight of the Glass Town (1809).
Appearance of the Russian Army in Sight of Stockholm
For seven days, for seven nights — slid,
leapt, jumped over the ice floes,
and knew: the south wind should once breathe —
and all will plunge down under.
O Swede, astounded shall you stare:
one frosty daybreak, one fine morning,
ice-clad and beautiful
from waves of whitish gray
emerge, in order, Russian cohorts,
and like a wolf ensnared,
the Swede gnaws off a hind leg —
he Finland throws to them:
Eat, choke, forever vanish
away from our own shores like smoke!
Thou brutal boar, thou beast accursèd!
Take up the keys of Lappenland,
but don’t – our crystalline, our clear-glass
old little town – pray do not crush!