Pour the vinegar into a large saucepan, add the sugar and spices and heat gently until the sugar has dissolved.
Add the peach halves and cook very gently for 4–5 minutes until just tender but still firm. Lift out of the syrup with a slotted spoon and pack tightly into a warmed large jar.
Boil the syrup for 2–3 minutes to concentrate the flavours, then pour over the fruit, making sure that the fruit is completely covered and the jar filled to the very top. Top up with a little extra warm vinegar if needed. Add a small piece of crumpled greaseproof paper to stop the fruit from rising out of the vinegar in the jar. Screw or clip on the lid, label and leave to cool.
After a few hours, the peaches will begin to rise in the jar, but as they become saturated with the syrup they will sink once more; at this point they will be ready to eat.
To serve, these peaches go well with slices of ham.