The Statute of Piotrków, containing the laws of Greater Poland, was composed between 1356 and 1362, and announced at a gathering in Piotrków. It was anterior to the statutes concerning Lesser Poland, promulgated at the gathering in Wiślica, in 1362 at the latest.

The statutes contain provisions concerning both the state system and judicial law (especially criminal law). They were not codifications in the modern sense, because they did not provide an exhaustive overview of any section of law, but they introduced, following canon law, the superiority of the established norm over the custom, which became an auxiliary norm.

Of the more interesting regulations relating to the social system, it is worth mentioning the punishment for murder (główszczyzna) and the Test of Nobility, which had to do, on the one hand, with the rising prominence of the knighthood (nobility) in public life and, on the other hand, with the lack of a specialised heraldic office controlling who belonged to the nobility. The Statute of Wiślica also confirmed the military service duty of knights, subject, however, to the privilege of being remunerated for serving abroad, which the knighthood had obtained as early as the thirteenth century.

Despite their incompleteness, the statutes of Casimir the Great played an important role in constructing a united kingdom and in amending existing legal norms. In the fifteenth century, the statutes of Piotrków and Wiślica were merged into one.

The achievements of Bolesław the Brave were also held in high esteem at the court of Bolesław Krzywousty (Bolesław Wrymouth), whose collaborators described them to the chronicler Gallus Anonimus who was writing a chronicle of the Piast dynasty. We do not know Gallus’s name or his country of origin. He is believed to have come from the south of France, although more recent research suggests that he may have hailed from northern Italy. He was probably a Benedictine monk. His Polish Chronicle, composed in Latin ca 1113 (its narrative stops at this date), describes the history of Poland since its mythical beginnings until the chronicler’s times. The author’s intent was to relate the deeds of Polish dukes, predecessors of Bolesław Wrymouth, and of Bolesław himself. It was doubtless a work intended to praise the ruler and his family, and to justify his title to the Polish throne. Gallus’s Chronicle is the first work of such breadth to have been written in Poland and treating of its history, hence despite its Latin and the author’s foreign origins it is considered the first work of Polish national literature. It remains a seminal and unrivalled source for the study of the early Piast period.

The power of Bolesław the Brave’s state – especially its military might – was lauded by the chronicler Gallus Anonimus, active at the court of Bolesław Krzywousty (Bolesław Wrymouth). We do not know his name or his country of origin. He is believed to have come from the south of France, although more recent research suggests that he may have hailed from northern Italy. He was probably a Benedictine monk. His Polish Chronicle, composed in Latin ca 1113 (its narrative stops at this date), describes the history of Poland since its mythical beginnings until the chronicler’s times. The author’s intent was to relate the deeds of Polish dukes, predecessors of Bolesław Wrymouth, and of Bolesław himself. It was doubtless a propaganda work meant to praise the ruling family and justify their title to the Polish throne. Gallus’s Chronicle is the first work of such breadth to have been written in Poland and treating of its history, hence despite its Latin and the author’s foreign origins it is considered the first work of Polish national literature. It remains a seminal and unrivalled source for the study of the early Piast period. In the fragment cited below, the chronicler provides numerical data regarding Bolesław the Brave’s troops which, however, are considered dubious and exaggerated by historians.

These events were described in contemporary annals and later chronicles. The circumstances of Mieszko’s baptism were related by an anonymous chronicler known as Gallus Anonimus, active at the court of Bolesław Krzywousty(Bolesław III Wrymouth). We do not know his name or his country of origin. He is believed to have come from the south of France, although more recent research suggests that he may have hailed from northern Italy. He was probably a Benedictine monk. His Polish Chronicle, composed in Latin ca 1113 (its narrative stops at this date), describes the history of Poland since its mythical beginnings until the chronicler’s times. The author’s intent was to relate the deeds of Polish dukes, predecessors of Bolesław Krzywousty, and of Bolesław himself. It was doubtless a work intended to praise the ruler and his family, and to justify his title to the Polish throne. Gallus’s Chronicle is the first work of such breadth to have been written in Poland and treating of its history, hence despite its Latin and the author’s foreign origins it is considered the first work of Polish national literature. It remains a seminal and unrivalled source for the study of the early Piast period.

Dating to the early period of Polish statehood, this document – known as Dagome Iudex after its opening words – was written down circa 991. It is known only from an abstract compiled in Rome in the late 11th century. By means of this deed, Mieszko, the first historical ruler of Poland, together with his wife Oda and their two sons, entrusts his realm, which was centred on Gniezno, to the safekeeping of the Apostolic See.

Historians have made various conjectures about the intention of this document. Some argue that papal custody was meant to protect the independence of the Polish Church against the claims of the archbishops of Magdeburg; others argue that the point was to ensure the participation of Mieszko’s sons from his second marriage (with Oda) in the ruling of the state. This would explain why Mieszko’s eldest son Bolesław Chrobry (Boleslaus the Brave), whose mother was the Bohemian princess, Dobrava, was not mentioned. The document describes the borders of the territory ruled by Mieszko in the late years of his reign, which lasted from about 960 to his death in 992.

In 965 or 966 he stayed in Magdeburg at the court of the newly crowned Roman Emperor, Otto I of Germany, with whom he talked, which may prove his visit had a parliamentary character. It is also probable that he learned in those court circles of the existence of an authority not known to him before, the “land of Mesko”. The content of the note does not indicate that he was to visit them personally. He wrote down the acquired information in his account, which has not been preserved in whole to this day, and which is known to us due to its use by Arab compilers: chronicler Al-Bakri in the 11th century (in his work entitled Book of Highways and of Kingdoms) and cosmographer Qazwini of Damascus in the 13th century (Book of Monuments of the Countries).

Since the 1878 edition prepared by W. Rosen and A. Kunik, the text of the Ibrahim ibn Yaqub account has been eagerly used as a source describing the functioning and organisation of the state of Mieszko I, including valuable information about the military in the early-Piast monarchy. According to Ibrahim, the strength of this largest of the Slavic countries state relied on effective and well-managed military units, which comprised, as estimated, 3000 men.