The 4th Regiment of Line Infantry was a military unit of the Kingdom of Poland. Formed in 1815, the regiment distinguished itself in the battles of the November Uprising and remains one of the best-known units of the Polish Army of the era. The soldiers of the regiment are known in Polish historical works as the Czwartacy. The regiment was not related to earlier 4th Advance Guard Regiment but rather was a direct descendant of the Napoleonic-era 4th Infantry Regiment of the Duchy of Warsaw. After Napoleon lost control of Poland in 1812, the regiment remained loyal to the emperor and fought in the bloody Battle of Leipzig and the Battle of Arcis-sur-Aube. After his abdication and exile to the Island of Elba, the remnants of the regiment returned to Russian-controlled Poland with their regimental flags, swore an oath to the Russian tsars and became the cadre of a newly formed infantry regiment with the same number. Their old regimental flag was retired and is preserved in the Warsaw-based Museum of the Polish Army. Officially named the "4th Regiment of Line Infantry", the soldiers of the new unit continued to use the nickname of Czwartacy, roughly "Men of the Fourth", which had achieved some notoriety. Like its predecessor, the new regiment was based in Warsaw and its main barracks was located in the Sapieha Palace. The regiment was recruited in and around Warsaw from a broad cross-section of society including noblemen, burghers, and large numbers of serfs and peasants. Because of the proximity of the barracks to the palace of Grand Duke Constantine Pavlovich of Russia, the 4th Regiment became one of his favoured military units and its soldiers enjoyed the status of his personal guard. In practice this often meant that the Grand Duke, very fond of his military units, but also cruel and brutal in their treatment, would march the soldiers of the regiment days and nights, in every weather. The morale in the maltreated regiment was low, yet any sign of discontent was brutally repressed: among those punished was the regiment's Major, a freemason, Walerian Łukasiński. Denounced as the founder of a secret society, he was sentenced to seven years of imprisonment, but eventually was held without trial for 46 years in Russian prisons, most of that in solitary confinement. Following the outbreak of the November Uprising, the regiment rebelled against the Russian tsars along with most of the army of the Kingdom of Poland. It fought from the very first day of the uprising and distinguished itself in the First and Second Battle of Wawer, as well as the battles of Dębe Wielkie, Ostrołęka and the final Battle of Warsaw. During the war the regiment received 214 Virtuti Militari crosses: five 3rd class, 55 fourth class and 154 fifth class. This made it one of the most highly decorated Polish units of the epoch. During the uprising the unit also was often referred to as "Tysiąc Walecznych" both by the press and general populace. This nickname was popularised in Europe by a German poetJulius Mosen, who published in 1832 a popular poem idealising the regiment and its actions during the war of 1830-1831.
