ENThe title of the article was taken from a letter written by a group of senators and sent on May 17, 1657, to Bohdan Khmelnytsky. The letter expresses the hope that Khmelnytsky together with the Zaporozhian army will support a reunion with the Republic of Poland. Also in other contemporary sources, we talk about connecting and uniting, about the Christian community. The author also recalls a book titled 350th anniversary of the Union of Hadiach (1658–2008), edited by T. Chynczewska-Hennel, P. Kroll, and M. Nagielski (Warsaw 2008). This collection of post-conference articles is a synthetic account of the results of a historical research carried out by scientists from Poland, Ukraine, Russia, Lithuania, Italy, Canada, and France. All researchers combine topics related to the history of the Union of Hadiach. Th e problem of the Union of Hadiach is connected to many issues referred to in the article but above all with the fundamental issue: linking the history of Ukraine with the political goals of Russia.