Hennell wrote offering his services in December 1939. He then offered services in return, simply, for food, accommodation and private soldier pay. He submitted some work to Clark and the Committee early in 1941 (7) and was advised to get in touch with the Ministry's advertising agency for poster work.
In March 1941, one of his pictures was purchased for seven guineas (LD 880). Later submissions were declined, before he was commissioned to make drawings of harvests (15ff) for 15 guineas. This work was done in Kent and submitted in October, resulting in the acquisition of LD 1476-1483. In February 1942, a further submission resulted in the acquisition of LD 1786-7, for 10 guineas the two (21); then, in November, LD 2157-8, for 5 guineas each (24).
In June 1943, Hennell was offered a three-month commission in Iceland, for £162.10s. He left on 31 July after some delay in the arrangements. Whilst in Iceland he had some problems with materials and wrote requesting paper; once this request was sent via his friend Vincent Lines (56). At (58) he describes his environment there: "the war effort is seen in a passive state and one turns for interest to local surroundings and people and being a civilian I am more naturally in touch with this". Corrected titles of some of his Icelandic pictures are at (124).
In January 1944 Hennell was commissioned for "fishing subjects", apparently as a stopgap before starting his "new naval duties" (ie salaried naval artist). He travelled to the north-east, to Northumberland, Yorkshire and Humberside, to make these, as described at (73-5).
A three-month commission was granted in April 1944, for Admiralty subjects in the Mediterranean (80) on the same terms as before, but this trip was postponed, apparently due to administrative delays. Meanwhile, Clark suggested that Hennell should make drawings of the invading embarkation preparations, and Hennell went quickly to Portsmouth at the end of May (84ff). Shortly afterwards, he was in France, following after the D-Day invasion. At (90), he expressed his gratitude to Clark for this opportunity. He mentioned that Ardizzone was with him.
A three-month commission was quickly sent to Hennell, which cancelled the 6-picture, 60-guinea commission which immediately preceded it (92). However, Hennell did not receive this commission, and wrote asking for permission to stay in the area at his own expense to make further work. He also wrote descriptions of his activities, among other matters. At (106), he reported that he was sharing a house with Albert Richards, who "secludes himself daily in intense concentration". He also proposed a book of his line drawings (109).
By late July 1944, Hennell was back at home in Kent, but he returned to France in August. Letters refer, among other matters, to three additional drawings of Portsmouth harbour, purchased for 25 guineas (125, 128); two pictures of WRNS censoring letters, and further drawings sent back in August (129). In (131) he refers specifically to being still with the Canadian unit, in early September. He then came in contact with new subjects: German prisoners of war, "a motive of great interest to me" (132) and "robot-bomb [V1] launching site", and mentions that Peter Scott is there. On the verso of (140) is a rough figure drawing, possibly of a prisoner of war.
Hennell's commission was extended for a further three months from September 1944 (134). By November, he was at a naval base in Belgium. He describes the limitations of transport, without a proper SHAEF press pass; mentions that he almost made it to see Anthony Gross, and a Canadian war artists' show. In December, his commission was renewed for a further three months (162).
In March 1945, Hennell was in hospital at Chatham after an operation, but was granted a six months contract to take effect after his recovery (177), this time for the Air Ministry. By June, he was in Burma, where he met up with Frank Wootton, whose case for better working conditions Hennell argued.(194, 198).
A list of drawings LD 5374-5390 is at (208).
Hennell mentions that Leslie Cole is also in Burma (210), some of whose work has been stolen. He mentions the possibility of visiting Java, and in (213) asks for direction where he should go next. He did travel to Java, from where he disappeared in November 1945 details of the supposed last sighting are at (215).
Post-war, papers primarily concern an Arts Council exhibition to which the IWM lent works. There is also a leaflet for the IWM exhibition of Hennell's work, 11 February to 13 May 1956.