Poland during the Piast dynasty in the context of "Lechites"

The House of Piast was the first historical ruling dynasty of Poland. The first documented Polish monarch was Duke Mieszko I (c. 960–992). The Piasts' royal rule in Poland ended in 1370 with the death of King Casimir III the Great.

Branches of the Piast dynasty continued to rule in the Duchy of Masovia (until 1526) and in the Duchies of Silesia until the last male Silesian Piast died in 1675. The Piasts intermarried with several noble lines of Europe, and possessed numerous titles, some within the Holy Roman Empire. The Jagiellonian kings ruling after the death of Casimir IV of Poland were also descended in the female line from Casimir III's daughter.

The last will and testament of the Piast duke Bolesław III Wrymouth of Poland, established rules for governance of the Polish kingdom by his four surviving sons after his death. By issuing it, Bolesław planned to guarantee that his heirs would not fight among themselves, and would preserve the unity of his lands under the Piast dynasty. However, soon after his death his sons fought each other, and Poland entered a period of fragmentation lasting about 200 years.

The Duchy of Silesia (Polish: Księstwo śląskie, German: Herzogtum Schlesien, Czech: Slezské knížectví) with its capital at Wrocław was a medieval provincial duchy of Poland located in the region of Silesia.

Soon after it was formed under the Piast dynasty in 1138, it fragmented into various Silesian duchies. In 1327, the remaining Duchy of Wrocław as well as most other duchies ruled by the Silesian Piasts passed under the suzerainty of the Kingdom of Bohemia as the Duchies of Silesia. The acquisition was completed when King Casimir III the Great of Poland renounced his rights to Silesia in the 1335 Treaty of Trentschin.

"Polish tribes" is a term used sometimes to describe the tribes of West Slavic Lechites that lived from around the mid-6th century in the territories that became Polish with the creation of the Polish state by the Piast dynasty. The territory on which they lived became a part of the first Polish state created by duke Mieszko I and expanded at the end of the 10th century, enlarged further by conquests of king Bolesław I at the beginning of the 11th century.

In about 850 AD a list of peoples was written down by the Bavarian Geographer. Absent on the list are Lechitic-speaking Polans, Pomeranians and Masovians, who became known later and were written about by Nestor the Chronicler in his Primary Chronicle (11th/12th century).