qualifications: experience of the events, proved ability to write lucidly and engagingly, [and] training as a historian". It was also decided that authors would not be able to write on topics in which they had played a leading part during the war. Selecting and engaging authors took up much of Long's time, and some potential authors declined offers of appointment. A replacement author for Chester Wilmot's volume on the Siege of Tobruk and Battle of El Alamein also had to be found in 1954 after he was killed in a plane crash. Once selected by Long, authors were confirmed by a committee comprising the Prime Minister, two or three other ministers and the Leader of the Opposition. Long and the general editor of the medical series were salaried and the other authors signed contracts to complete their work within a specified time frame and were paid in instalments as parts of their work were delivered. Of the 13 principal authors, five were academics and five were journalists. The official historians were supported by salaried research assistants who were members of the Australian Public Service and the project was administered by the Department of the Interior. Long retired in 1963, and his assistant Bill Sweeting assumed the role of editor. Although the series was funded by the Australian Government, the authors were free to write on all topics other than technical secrets that were classified at the time, and were not otherwise censored. In line with a request by the US and British governments, the official historians in Australia, Britain, Canada, New Zealand and the US were not given access to Ultra intelligence gained from decrypting German codes. The vetting process for the volumes in the series also sought to ensure that they did not disclose that German codes had been broken, as this was still classified at the time. Long may have not even been informed that German or Japanese codes had been broken. The authors were given unrestricted access to all other official records, and the Army, Navy and Air series were mainly based on these records and the hundreds of interviews Long had conducted with Australian military personnel during the war. German, Italian and Japanese records were also used to provide information on the enemies the Australian military fought. Draft chapters were sent for comment to the official historians in Britain, New Zealand and the United States. The