Ludvig Nikolaus von Hallart (1659-1727), a Saxon by birth, was a baron, general, and highly appreciated associate of Tsar Peter the Great. His military career can be regarded as the most successful when compared with those of other foreign commanders who joined the Russian army under the reign of Tsar Peter I. Before 1700 Ludvig von Hallart served in the Saxon army as a general-engineer. In 1700 Frederick Augustus II, Elector of Saxony and King of Poland, recommended him to the Russian Tsar. Soon thereafter Hallart joined the army of Peter I, which was then encamped near the fortress of Narva. He was promoted to lieutenant-general, and was responsible for building artillery pieces, trenches and other earthworks near the fortress of Narva. After the Russian defeat in the Battle of Narva (1700), he and some of the other commanders of foreign origin were suspected of treason and were forced to seek refuge in the Swedish camp. General Hallart was in captivity in Sweden until 1706 when he was exchanged for the Swedish commandant of Narva, General Henning Rudolf Horn. After his discharge he was appointed ambassador to the court of Tsar Peter I. In the year following Augustus’ death, Hallart renewed his service in the Russian army, which was at the time encamped near Grodno. He supervised the strengthening of important strategic fortresses Polotsk and Kopys and participated in many clashes with the Swedes during the military campaign near Grodno. In the beginning of 1708, the Swedish army approached the border of the Russian state and skirmishes between the opposing sides became more frequent. Baron Hallart was given the command of 10 infantry regiments, the most battle-worthy units of the Russian army, to respond to the Swedish attacks. He retreated to Mogilev at the head of the formation of his regiments, and then tried to repulse the Swedes in the Battle of Holowchin. This operation was, however, unsuccessful. General Hallart later attempted to hold back the enemy on the bank of the Desna River near Novgorod-Seversky but failed again. Unlike many commanders he was not punished by Peter I for these misfortunes. However, it was not until the Battle of Poltava that his luck finally turned. As the commander of the Third Infantry Division he displayed courage and heroism in leading his troops to success, and was awarded the Order of St. Andrews. In 1711 Hallart took part in the unsuccessful Russian campaign at the River Prut. In the following year, he was given the overall command of the Russian, Danish, and Polish troops deployed in Pomerania near the fortress of Stralsund, but was soon dismissed at the request of Alexander Menshikov. Offended by the decision Hallart resigned and returned to Volmarshof, his estate in Livonia that had been granted to him as a life estate by Peter I. However, he returned to military service in 1721 and took command of all troops deployed in Ukraine. In 1723 Hallart transferred command to General Golitsyn and proceeded to St. Petersburg to stay at the court. In 1725 he was awarded Order of St. Alexander Nevsky by Empress Catherine II. Soon thereafter he retired and spent the rest of life on his estate. Among his contemporaries Hallart was distinguished by his extensive knowledge and expertise in the field of engineering. He was well known for his excellence in designing and building fortifications, and left a collection of plans of more than 600 European fortresses. He is also well known as one of the first historians of Peter I. His unfinished history of the Russian tsar is preserved in the library of the Hermitage in St. Petersburg.