Odrodzenie i Reformacja w Polsce PL ISSN 0029‑8514 Special Issue Tomasz Kempa (Toruń) Unknown letters of the Metropolitan of Kiev Hipacy Pociej, an important source on the beginnings of the Brest Union e Uniate Metropolitan of Kiev, Hipacy (his secular name being Adam) Pociej (1541‑1613) was among the most interesting, but at the same time most controversial personnages of the Commonwealth at the turn of the sixteenth and seventeenth centuries. 1 is was because of his involvement in a fraught with consequences internal conflicts of the Polish‑Lithuanian state, and namely the argument between the support‑ ers and opponent of the Brest Union (1595/96), that took place on the religious (in a polemical way) as well as political and legal planes. e conflict – as each one with underlying religious issues – stirred emotions of the nobility, particularly in eastern regions of the Commonwealth, and occasionally it turned violent. Also Hipacy Pociej contributed to this, 1 No exhaustive biography of Pociej has been written to date, although there are several publications devoted to him; majority of them date from the nineteenth and early twentieth centuries: N. Tripolskij, ‘Uniatskij mitropolit Ipatij Potiej i jego pro‑ powiedniczeskaja diejatelnost’’, Trudy kiewskoj duchownoj akademii, 1877, no. 10, pp. 123‑81; O. Lewickij, ‘Ipatij Potiej, kiewskij uniatskij mitropolit’, Pamiatniki russkoj stariny w Zapadnych gubiernijach, 8, 1885, pp. 342‑74; M. Czubatij, Mitropolit Ipatij Potij – apostoł cerkovnoj jednosti, Lvov, 1914; Juwiliejna kniga w 300‑rokowini smierti mitr. I. Potija, Lvov, 1914 (a lengthy biographical note is found on pp. 31‑133, by Sawickij); A. Piekar, ‘Ipatij Potij – prowisnik zjedinennia’, Analecta Ordinis Sancti Basili Magni, 15, 1996, pp. 145‑246. Recently, a popular work on Pociej has been published: S.A. Padokszyn, Ipacij Pacej. Carkouny dzejacz, myslicel, pismiennik na pierałomie kul‑ turna‑histarycznych epoch, Minsk, 2001. Cf. the entry J. Dzięgielewski, Pociej Hipacy, in Polski Słownik Biograficzny, vol. 27, Wrocław, 1982‑83, pp. 29‑34. http://dx.doi.org/10.12775/OiRwP.SI.2014.11