Summary: A detailed electron probe study of irontitanium oxide intergrowths from slowly cooled granitic rocks from the granulite grade, Archaean Scourian complex of north-west Scotland has yielded a wealth of information about magmatic and metamorphic temperatures, subsolidus cooling, and the behaviour of the fluid phase during cooling. Five stages are documented in the cooling history of granites and trondhjemites which include: (i) magmatic-subsolidus cooling (1035 °C–890 °C); (ii) granulite facies metamorphism and the accompanied expulsion of a hydrous fluid phase (890 °C–830 °C); (iii) subsolidus cooling following the peak of the granulite facies metamorphism (830 °C–660 °C); (iv) the localized reintroduction of water into the rocks during retrogression (660 °C–530 °C) and (v) subsolidus cooling and re-equilibration in the presence of a finite amount of H₂O (530 °C–320 °C).