Abstract Detailed investigations of metamorphism and migmatization in the northern archipelago of Misterhult, south of Vastervik, SE Sweden, show that two main events can be distinguished: 1. Period of prograde metamorphism: the maximum phase being a high-stage paragenesis with K-feldspar and sillimanite. Fleck and veined gneisses are formed, the former due to porphyroblastic growth (e. g. cordierite, andalusite) and/or metamorphic differentiation, the latter most likely due to metamorphic differentiation. A rise in fH2O and aK+ occurred, connected with the prograde metamorphism of argillaceous rocks (i.e. the breakdown of muscovite). 2. Period of retrograde metamorphism: the most intense stage being equal to “greenschist facies”. Raft migmatites and probably the major part of the agmatites form; the former by introduction of a K-rich volatile phase (from the younger granites) into a metasediment-metabasise-sequence, the latter due to the effect of non-hydrostatic pressure and the intrusion of a K-rich ph...