Place the sugar and 130ml water in a pan, heat gently until the sugar has dissolved, bring to the boil and simmer for four minutes then remove from the heat and leave to cool.
Damsons are near impossible to stone so to get rid of the stones, place the damsons and 4tbsp water in a separate pan and cook gently until the damsons have softened and broken down. Press the fruit through a sieve or chinois to get rid of the stones, take your time and really scrape it through to get as much fruit puree as possible.
Mix together the damson puree, sugar syrup and gin, cover and refrigerate until completely cold then freeze in an ice cream maker according to the manufacturers instructions.