A process to prepare a first middle distillates fraction, a second middle distillates fraction, a distillate base oil and a residual base oil by providing a Fischer-Tropsch product stream; separating the Fischer-Tropsch product stream to obtain at least a low boiling fraction, boiling below a temperature ranging from 300 to 450° C., and a high boiling fraction, boiling above a temperature ranging from 300 to 450° C.; subjecting the high boiling fraction to a hydrocracking/hydroisomerization step to obtain a partially isomerised product stream; separating the partially isomerised product stream to obtain a first middle distillates fraction, a heavy distillates fraction and a residual fraction, the residual fraction having a T5 wt. % boiling point between 400 and 650° C.; dewaxing the low boiling fraction to obtain a second middle distillates fraction; dewaxing the heavy distillates fraction to obtain a distillate base oil; and dewaxing the residual fraction to obtain a residual base oil.