During the Great Northern War (1700–1721) Sheremetev proved a capable but cautious and sluggish military leader.
For much of the war he served as the commander-in-chief and most senior officer in the Russian army.
Sheremetev was very cautious in his movements but proved more effective than the younger  Prince Menshikov, the second-in-command, whose impulsiveness did not always lead to success.

In 1700 he joined the Russian army in its attack on Narva at the outbreak of the Great Northern War, but King Charles XII of Sweden drove him back from his position in Estonia.
He then became commander of the Russian forces fighting the Swedish armies in the Baltic provinces.
Colonel W. A. Schlippenbach defeated Sheremetev at  Rauge in September 1701, but the Russians turned the tables on Schlippenbach (now a Major-General) at Erastfer in December 1701.
This victory won Sheremetev the title of field marshal, and another Russian victory ensued at the battle of Hummelshof in July 1702.
 Sheremetev's army's attack on Marienburg (August 1702) led to Martha Skavronskaya coming to the tsar's court, where she eventually became Empress Catherine I (reigned 1725-1727).

Sheremetev took the Swedish Ingrian fortresses of  Nöteborg (October 1702) and Nyenskans (1 May 1703) (allowing the foundation of the city of Saint Petersburg later in May 1703)) and the important Baltic cities Dorpat and Narva in 1704.
In 1705 Peter I sent him to Astrakhan, where he forcefully and successfully repressed the Cossack Astrakhan revolt of 1707-1708.

In the course of the Great Northern War, Sheremetev clashed with the Swedish general Lewenhaupt, who beat him at Gemäuerthof in July 1705, and Charles XII, who defeated him at Holowczyn (July 1708).
Sheremetev's revenge came at the Battle of Poltava in 1709, where he functioned as the senior Russian commander of the forces which soundly defeated the Swedish army.
Armies under his command conquered Riga in 1710.
Sheremetev then led the  main forces of the army against the Ottomans in the  Prut campaign of 1710-1711.
Fighting against Turkey in 1711, he suffered encirclement at the Battle of Stănileşti on the Prut (July 1711).
In 1715–17 Sheremetev commanded armies in Pomerania and in Mecklenburg.

Although sympathetic to Peter I's policy of Westernising Russia, Sheremetev never became close to the tsar.
He died in 1719 in Moscow; Peter I had him buried in the Lazarevskoe Cemetery in St. Petersburg.
During the Great Northern War (1700–1721) Sheremetev proved a capable but cautious and sluggish military leader. For much of the war he served as the commander-in-chief and most senior officer in the Russian army. Sheremetev was very cautious in his movements but proved more effective than the younger  Prince Menshikov, the second-in-command, whose impulsiveness did not always lead to success.
In 1700 he joined the Russian army in its attack on Narva at the outbreak of the Great Northern War, but King Charles XII of Sweden drove him back from his position in Estonia. He then became commander of the Russian forces fighting the Swedish armies in the Baltic provinces. Colonel W. A. Schlippenbach defeated Sheremetev at  Rauge in September 1701, but the Russians turned the tables on Schlippenbach (now a Major-General) at Erastfer in December 1701. This victory won Sheremetev the title of field marshal, and another Russian victory ensued at the battle of Hummelshof in July 1702.  Sheremetev's army's attack on Marienburg (August 1702) led to Martha Skavronskaya coming to the tsar's court, where she eventually became Empress Catherine I (reigned 1725-1727).
Sheremetev took the Swedish Ingrian fortresses of  Nöteborg (October 1702) and Nyenskans (1 May 1703) (allowing the foundation of the city of Saint Petersburg later in May 1703)) and the important Baltic cities Dorpat and Narva in 1704. In 1705 Peter I sent him to Astrakhan, where he forcefully and successfully repressed the Cossack Astrakhan revolt of 1707-1708.
In the course of the Great Northern War, Sheremetev clashed with the Swedish general Lewenhaupt, who beat him at Gemäuerthof in July 1705, and Charles XII, who defeated him at Holowczyn (July 1708). Sheremetev's revenge came at the Battle of Poltava in 1709, where he functioned as the senior Russian commander of the forces which soundly defeated the Swedish army. Armies under his command conquered Riga in 1710. Sheremetev then led the  main forces of the army against the Ottomans in the  Prut campaign of 1710-1711. Fighting against Turkey in 1711, he suffered encirclement at the Battle of Stănileşti on the Prut (July 1711). In 1715–17 Sheremetev commanded armies in Pomerania and in Mecklenburg.
Although sympathetic to Peter I's policy of Westernising Russia, Sheremetev never became close to the tsar. He died in 1719 in Moscow; Peter I had him buried in the Lazarevskoe Cemetery in St. Petersburg.
Boris Sheremetev