There are particular bound states of D 7 -branes, known as ’T-branes’, that show interesting features which cannot be achieved by a stack of ordinary branes (e.g. the gauge group of n coincident branes may not be U (n)). This means that the physics is not only dictated by the geometry of the space given by the spectral polynomial of the world-volume scalar. The idea of this project is to analyse T-branes of perturbative type IIB string theory. We work with compactifications to six space-time dimensions, and we look for the BPS equations, which are the equation of motion of the background fields. Finally, with a particular focus on SU (2) and SU (3) gauge theory, we investigate local and global properties of the perturbations of the Higgs field around T-branes.