Agnes was born in 1137/1138 [2, p. 7; 3, p. 230] Boleslaw III Wrymouth and his second wife Salomea of Berg. She was the eleventh of twelve children and her father had various plans for her future; he even considered up to sending her to a monastery [11, p. 161-162]. However, at the meeting in Łęczyca organized by Agnes’s mother, it was decided to marry Agnes “the son of the king of Rus’” [VII, p. 91-92]. In the political context, such a decision could be conditioned both by the desire to prevent Wladislaw II from the alliance with the Russian princes, and by a mere will to strengthen ties with Galicia-Volynia. Most researchers share the point of view first expressed by M. Korduba that the unnamed “Russian prince” in Ortlib’s description of the meeting in Łęczyca is actually Mstislav Izyaslavich [13, p. 30-31]. D. Dombrovski, however, argues that Mstislav was not the only possible “son of the king of Rus’” and names at least two more possible persons who would also fit such a description [3, p. 226]. Dombrovsk notes, however, that the marriage of Agnes with Mstislav is beyond any doubt, but it is not possible to reconstruct thoroughly how the groom has been chosen.
The wedding of Agnes and Mstislav cannot dated with precision. The date which is accepted in the literature is 1151 or 1152 [12, s. 262–263] was proposed by O. Balzer . [8, p. 321-322]. Basing on the age of the sons born in the marriage, above all, Roman Mstislavich, D. Dombrovski corrected the possible date of the wedding and supposed that it took place between 1149 and 1151 [3, p. 228-230]. After the death of Izyaslav, Mstislav Izyaslavich participated in civil wars, relaying on the support of Piast, Agnes was also fully involved in this conflicts [7, p. 52]. After the death of Izyaslav, while fleeing from Yuri Dolgoruky and Izyaslav Davydovich, Agnes was sent to Lutsk [II, col. 475]. The description of this retreat in the Hypatian Chronicle (Letopis) allowed to suppose that Agnes was pregnant at that time. However, the Chronicle of Master Vincent [VI, p. 156] reports that the marriage of Agnes and Mstislav has remained childless for a long time. It is also known that at least three sons were born in the marriage (including Roman Mstislavich, who was brought up at the Polish court). The origin of Roman, Vsevolod and Vladimir is beyond any doubt. It is not completely clear whether the eldest son, Svyatoslav, was in fact the son of the couple. Many scientists disputed about this fact, because of the message of Wincenty Kadlubek, who cited Agnes’s own words that Svyatoslav was a foundling who the discovered having lost all hopes to of having children [VI, s. 215]. Some other account corroborate with Kadlubek’s description and call Roman Mstislavich the firstborn [IV, s. 638; V, s. 483; 9, s. 122-123, 166-168]. Some scholars believe that Svyatoslav was Mstislav’s bastard from an unknown woman [1, p. 48-49; 12, s. 263]. Other historians hypothesize that the war which his brothers started against him immediately after the death of Mstislav Izyaslavich and which was largely initiated by Agnes herself speaks rather in favour of this his legitimate rights to the princely throne by right of primogeniture [3, p. 252-253; 10, s. 121].
In any case, the reasons why Agnes disliked the elder Mstislavich so much remain mystery.
When Mstislav had accessed the throne of Kiev in 1167, Agnes became the princess of Kiev. Two years later, in 1169, along with her sons she was captured by Andrei Bogolyubsky (Andrei the Pious), who seized Kiev [4, p. 11]. Mstislav was forced to flee to Volhynia, but a year later he regained both the city itself and the title of Grand Prince of Kiev. Having lost the support of his allies including Piasts, Mstislav could not retain his power for a long time. Just a month after his return, he was forced to flee one more time; in August 1170 Mstislav dies.
The exact date of Agnes’s death remains unknown. The last record about her dates back to 1182. At this time, the grown sons of Mstislav struggled for power in Galicia-Volynia. Roman and Vsevolod opposed their older brother, Svyatoslav. Agnes, apparently, was involved in this conflict supporting Roman and Vsevolod. With the support of his uncle Casimir the Just, Svyatoslav managed to return Brest, taken by his brothers. He subsequently reigned in the city until his death.
I. Polnoe sobranie russkikh letopisei (PSRL). T. 1. Lavrent'evskaia letopis' M., 2001.
II. PSRL. T. 2. Ipat'evskaia letopis'. M., 2001.
III. PSRL. T. 38. Radzivilovskaia letopis'. L., 1989.
VI. Kronika wielkopolska / Wyd. B. Kürbis // Monumenta Poloniae historica. T.VIII. Warszawa, 1970.
V. Magistri Vincentii dicti Kadłubek Chronica Polonorum / Ed. M. Plezia // Monumenta Poloniae historica (Pomniki dziejowe Polski). T. XI. Kraków, 1994.
VI. Mistrz Wincenty Kadłubek. Kronika polska. Przeł. i oprac. B. Kurbis. Wrocław-Warszawa, 2003.
VII. Ortliebi de fundatione monasterii Zwivildensis libri II // Monumenta Germaniae Historica. Scriptores / Ed. G.H. Pertz. T. X. Hannoverae, 1852.
1. Golovko O. Kniaz' Roman Mstislavovich ta iogo doba. Kiїv, 2001.
2. Gorovenko A. Mech Romana Galitskogo. Kniaz' Roman Mstislavovich v istorii, epose i legendakh. SPb., 2011.
3. Dombrovskii D. Genealogiia Mstislavichei. Pervye pokoleniia (do nachala XIV v.) / Per. s pol'skogo i vstup. slovo k rus. izd. K. Iu. Erusalimskogo, O. A. Ostapchuk. SPb., 2015.
4. Drevniaia Rus' v srednevekovom mire: entsiklopediia / Pod obshch. red. E.A. Mel'nikovoi, V.Ia. Petrukhina. M., 2014.
5. Morozova L.E. Velikie i neizvestnye zhenshchiny Drevnei Rusi. M, 2009.
6. Presniakov A.E. Kniazhoe pravo v Drevnei Rusi. Lektsii po russkoi istorii. Kievskaia Rus'. M., 1993.
7. Shchaveleva N. I. Pol'ki – zheny russkikh kniazei (XI – seredina XIII vv.) // Drevneishie gosudarstva na territorii SSSR. 1987 g. M., 1989. S. 50–58.
8. Balzer O. Genealogia Piastów, Wyd. II. Kraków 2005.
9. Dąbrowski J. Dawne dziejopisarstwo polskie. Wrocław, Warszawa, Kraków, 1964.
10. Dobosz, J. Kazimierz II Sprawiedliwy. Poznań, 2011.
11. Grodecki R. Dzieje Polski do 1194 // R. Grodecki, S. Zachorowski, J. Dąbrowski, Dzieje Polski średniowiecznej. Kraków, 1926. S. 161–162.]
12. Jasiński K. Rodowód Piastów małopolskich i kujawskich Poznań; Wrocław: Wydaw. 2001.
13. Korduba M. Agnieszka // Polski Słownik Biograficzny. T.1. Kraków, 1935.