According to the Polish-Czech writer and heraldist Bartosz Paprocki, this coat of arms is called Jastrzebiec because the clan's pagan ancestors bore a Goshawk, or Jastrzab.

[2] In the era of King Bolesław the Brave, circa 999, during a siege of the mountain fortress Łysa Góra – two miles from Bozecin, now called Swiety Krzyz (Holy Cross) – the Christian besiegers were challenged by the pagan holders of the place, to "Send forth one from among you who is willing to fight for Christ, in a challenge against one of our men."

Jastrzebczyk, a knightly member of the Jastrzebiec clan invented horseshoes that enabled his horse to climb the slippery slopes and to defeat and bring the pagan champion before the king.

In gratitude, king granted Jastrzebczyk the right to bear a horseshoe with a cross as part of his arms, with the Goshawk being elevated above the shield.

Not until after the days of Archbishop Wojciech of Gniezno did foremost members of this house began to write z Rytwian ("from Rytwiany").

Based on a grant of privilege to a monastery in 999, Paprocki cites the most ancient member of this house as being a castellan of Sandomierz, a man named Mszczuj.

Paprocki cites a fragment of his in O herbach, but the long stretch of time between them and their father, 166 years, indicates that they were not the sons of Derszlaw the cup-bearer.

Paprocki writes that in Jędrzejów a grave from the year 1206 is covered with a stone on which the Jastrzębiec arms are still visible, but the letters can no longer be read.

A letter of Kazimierz the Great, King of Poland, given to the Strzelno monastery, mentions, inter praesentes, Mszczuj, Kraków chamberlain.

Jedrzej, Bishop of Vilna, called "Vasilo" by the Lithuanians, was an apostolic shepherd in the days of King Władysław II Jagiełło.

Marcisz, brother of Bishop Jedrzej, endowed the Franciscan Fathers in Nowe Miasto with a monastery and he bought Zborów, from which came the family of Zborowskis.

Remember, when you have become a bishop, do not forget your current standing, in which you see both your mother and me, your brothers and sisters: this lack of means in which you were born is greater than could fade from your memory if you had the greatest fortune.

When you become a bishop, do this for me, make a church of brick in this place where I give you up for schooling.Wojciech listened to all of this and promised to fulfill the exhortation as a paternal order.

Then in 1423, he was elevated to the rank of metropolitan and primate, and there left a memory of his generosity, funding two benefices, one theological and one juridical, as well as a third in Kalisz.

He set up an altar in Leczyca, returned regular canons to Klodawa, and raised their church to collegiate rank.

He died in 1436, an important, judicious man and a great lover of his country, as Dlugosz and Damalew praised him in Vitae Archiepisc.

From that time, Wojciech's successors began to sign their names as z Rytwian ("from Rytwiany"): his brother was Scibor, voivode of Leczyca, who had twenty sons.

[2] In the Jastrzębiec family, there is also the case of a man from the Witowski family, who, on the basis of his marriage, left for Russia, from where, in the next generation, a high-ranking aristocrat Katarina Wiltawsky returned to the vicinity of Krakow, who married a Polish German (Pruska), who took her surnames and Russian titles of nobility.

Upon a wreath of the colors mantled of his liveries whereon is set for a crest: out of a ducal coronet, a hawk proper, wings surgent, belled and jessed, holding in its dexter talons, a charge of the shield.

The tinctures (colors) are as follows: azure = blue; gules = red; sable = black; or = gold; argent = silver; and vert = green.