Copies of letters sent by Walker during the first and first part of the second cruise of the Royal Family squadron. The letters cover the squadron’s actions against French and Spanish shipping, but also include details about the oversight of provisions, financial accounts and the organisation and discipline of the crew. There is also an account of the murder of William Sullivan, which took place on board the DUKE on the 30 April 1746. The majority of the letters are to the squadron's owners. The letter book also copies of orders to Walker from the owners and from Walker to his officers and crew at the back of the volume.