The invention relates to polysaccharide graft polymers useful for incorporation as benefit agents in laundry detergent and fabric treatment compositions, and their preparation. The invention also relates to substituted polysaccharides useful as macroinitiator intermediates for the preparation of the polysaccharide graft polymers, and the preparation of the macroinitiators. The polysaccharide graft polymers may be used, for example, to impart soil release and/or fabric care benefits to laundry detergent or fabric treatment compositions.