The XXIII Session of the Petrology Group of the Mineralogical Society of Poland will be devoted to recent studies on the subduction systems in the Sudetes and related areas and ancient and current analogues. As during previous meetings, the aim of the Session is to gather all Polish petrologists including seniors, early career scientists as well as graduate and undergraduate students. A set of international invited speakers will let us exchange ideas and mingle with the top-notch researchers in the field. We cordially invite you to participate in this meeting. All contributions including those not exactly related to the leading theme of the Session are warmly welcome.