For one and a half a decade, between 1370 and 1385, Poland was under rule of neither the famous Piasts nor the Jagiellonians. During those 15 years, King Louis the Great of Andegawen become a king of Poland, after the Polish Piast rulers died out in 1370.

Louis' mother was Elizabeth, the daughter of Ladislaus the Short, the sister of Casimir III the Great, king of Poland.

Jadwiga, queen of Poland (called also Saint Hedwig or Hedwig of Anjou) (1374 - 1399) succeeded her father, King Louis the Great on the Polish throne in 1384 following a two-year interregnum. Her reign saw the start of Poland's dynastic union with neighbouring Lithuania, and the latter nation's conversion to Christianity.

Both her mother, Elizabeth, and grandmother, Elizabeth Lokietkówna, were from the Piast dynasty which had ruled Poland from IX century until 1370, and she was the granddaughter of King Ladislaus I, who had reunited Poland earlier in the century.

Jadwiga was betrothed to William of Habsburg. From the age of eight she lived at the Imperial court in Vienna. Her father had also made an arrangement with the future Holy Roman Emperor Sigismund for the latter to marry either Jadwiga or her sister Mary, later queen of Hungary (Sigismund married Mary.)

Jadwiga had to return to Poland when her sister Catherine died in 1378. When her father died in 1382, the archbishop of Krakow crowned her as "Jadwiga, king of Poland" - technically speaking, she was king, not queen. The nobility of Poland prevailed upon her to end her engagement with William and instead to marry Jagiello, grand duke of Lithuania, whose country had returned to paganism after a brief peiod of Christian kingship in the 1250s. In February 1386 Jagiello converted to Catholicism, and shortly afterward they were married. Jagiello was crowned king of Poland as Ladislaus II.