Neither Portland nor the Admiralty sent him a reply .
Granville Sharp campaigned to raise awareness of the massacre , writing letters to newspapers , the Lords Commissioners of Admiralty and the Prime Minister ( the Duke of Portland ) .
Neither Portland nor the Lords Commissioners of Admiralty sent Granville Sharp a reply .
Granville Sharp campaigned to raise awareness of the massacre , writing letters to newspapers , the Lords Commissioners of Admiralty and the Prime Minister ( the Duke of Portland ) .