Final Activity Report Summary - USO-SP (USO-SP International graduate school for solar physics) The sun is our nearest star and of obvious importance for our daily lives by its warmth and by driving the space-weather that can wreak havoc with our technological environment. It is of great importance in astrophysics as a stepping stone to the stars and as a physics laboratory where matter and energy can be studied in circumstances impossible to create on Earth. The USO-SP International Graduate School for Solar Physics aimed at combining the skills and assets of three solar-physics institutes to help fostering a new generation of European solar physicists. The institutes are referred to with their home cities: 1 - KVA, Stockholm (S), Coordinator 2 - UU, Utrecht (U) 3 - UiO, Oslo (O). The two solar telescopes on La Palma are run from Stockholm (Swedish 1-m Solar Telescope, SST) and Utrecht (Dutch Open Telescope, DOT).The School recruited two PhD students per institute who would use their 3-year Marie Curie Fellowships to pursue PhDs. (In S and U a fourth year is needed for a PhD, this is paid by the respective contractors.) In addition, a number of shorter Traineeships were filled over the project period. A major success of the project is that each Trainee who did not already have a PhD position got one afterwards. Every Traineeship will thus hopefully lead to a PhD.Three major schools in solar physics were organised, as well as two smaller ones and a range of meetings and networking events. However, the human product of the project is the most important, and thus this account follows the individual Fellows which are designated with their location (U, S, or O) and PhD or Tr for PhD student or Trainee.Leandro Jesus (O-PhD) aimed at the stars by using solar coronal modelling to investigate solar-like stars in general. Juan Martinez Sykora (O-PhD) made the first numerical simulations of magnetic flux reaching from below the chromosphere into the corona. Jaime de la Cruz Rodriguez (S-PhD) studied convective Doppler shifts of spectral lines and pushed the limits of SST polarimetry to probe the chromosphere. Vasco Henriques (S-PhD) developed the SST blue imaging diagnostic to map photospheric temperatures. Catherine Fischer (U-PhD) investigated solar magnetic fields using data from many sources. Nikola Vitas (U-PhD) attacked spectral-line-formation problems with interesting implications - e.g. the variation of lines with solar activity and the abundance of indium and oxygen. The solar oxygen abundance was also determined by Tiago Pereira (S-Tr) who acquired SST spectra of oxygen lines.A very important contribution to the solar-atmosphere modelling was made by Jorrit Leenaarts (O-Tr) who included realistic time-dependent ionisation of hydrogen in atmospheric simulations. Important numerical work was done by Wolfgang Hayek (O-Tr) who developed a 3D radiative transfer code for massively parallel applications.