Józef Piłsudski was born in December 1867 and died in May 1935. One of the key and most important figures in the history of 20th-century Poland, who is considered the "father" of independent Poland. Before the outbreak of World War I, Józef Piłsudski was an active independence activist and a member of the PPS party. Shortly before 1914, he, together with his companions and the Russian gold plundered in Bezdany, broke from the Russian partition to the Austrian one, where he began creating Polish patriotic organizations, the so-called shooting organizations. Shortly after the outbreak of World War I, he tried to provoke a national uprising in Poland (Kielce region), which, however, ended in a complete defeat. Soon after, along with his troops, he joined the forming Polish Legions. He quickly gained enormous prestige and almost total devotion from his subordinates. He also led to the so-called the oath crisis that resulted in him being imprisoned in the fortress in Magdeburg. After being released from the fortress in November 1918, he reached Warsaw, where he was given the authority over the already formed and emerging Polish army from the local authorities. Józef Piłsudski entered the most important period of his life, becoming after 1918 the Head of State, the Temporary Head of State, but also a person who created the so-called federation concept. It was then that he also won the Battle of Warsaw in August 1920, making it a part of the history of the Polish army as one of the best Polish commanders of the 20th century. In 1922, he resigned and settled in Sulejówek - in a villa purchased for his use by his former subordinates. In 1926, he returned to active politics, co-organizing a military coup, which went down in history as the May coup and which handed over power to a political camp closely related to Józef Piłsudski. This camp, also known as the Sanacja, remained in power until 1939. During this period, democracy in Poland was significantly limited or - as others want - its destruction, which may be indicated by, for example, the rigged Brzeg elections of 1930, preceded by the arrests of political opposition leaders or the unlawful adoption of the April constitution in 1935. Józef Piłsudski died on May 12, 1935 (the anniversary of the May coup!) After a long illness, which was hidden from the public opinion. Despite the controversy he raises, he is undoubtedly one of the most important figures in the history of Poland in the 20th century.The Polish-Bolshevik war of 1919-1921 was the most important military conflict of the reborn Poland, and the Warsaw Battle fought in its course - perhaps the greatest Polish military success in the history of the 20th century. It is worth adding that from its beginning, until the beginning of the summer of 1920, the Polish side was the attacking party, shifting its influence decidedly to the east - at its peak, all the way to Kyiv. In its course, attempts were also made to implement the so-called the federalist concept of the Polish eastern border. However, from June-July 1920, in connection with the huge offensive of the Red Army under the command of Mikhail Tukhachevski, the Polish side was pushed to the defensive and to the defense in the suburbs of Warsaw. In this difficult situation, Józef Piłsudski, the head of state, remained calm and managed to carry out the so-called counterattack from the Wieprz River, which forced the Soviet troops to retreat. The success of the Battle of Warsaw was later repeated in the course of the German operation. Finally, the war ended in 1921 with the signing of the peace treaty in Riga, which regulated the Polish-Soviet border until September 17, 1939. It is worth adding that in this armed conflict, the nascent Polish Army was heterogeneous, consisting of units of very different provenance, among them - soldiers of the Polish Legions, the Blue Army, the Greater Poland army and recruits recruited in 1919 and 1920. Also, the equipment, equipment and tactics of individual units were often very different. It is assumed that theoretically, the position of the Polish infantry division from 1919-1921 consisted of the command, two infantry brigades (two infantry regiments each), artillery brigade, sapper battalion, cavalry squadron, telegraph company and caravans. But, for example, the infantry divisions of the Blue Army had a structure based on three infantry regiments, and in the case of the so-called Instructional Division - by five regiments. Therefore, it is virtually impossible to give a uniform structure of the Polish infantry division in the years 1919-1921. It is worth adding, however, that at the peak of hostilities, the Polish side deployed about 1.1 million soldiers, a number similar to that of the September 1939 campaign.