In his drawings, Henry Moore frequently invented sequences of sculptural forms. They were organised in real space with effects of light, shade and modelling. A single subject was treated with variations, and the interior-exterior forms in this work are gathered in a family of seven. A related work of the same subject included eight such forms organised in a more regular composition of two consecutive rows (fig. 1). These and a series of other drawings made in 1948–50 depict a subject that Moore originated in 1939, the helmet-head, which Kenneth Clark described as ‘the cranial equivalent of the internal-external forms; heads which should have the same degree of metamorphosis, and the same intensity, as the bodies of his reclining figures.’ This form originated in drawings and was subsequently adopted as the subject of sculptures cast in lead and bronze, first in The Helmet (1939–40, LH 212), then further works in 1950 (LH 279–83), 1952 (LH 303, 304), 1960 (LH 467), 1963 (LH 508), and 1975 (LH 651).

Moore’s helmet form is anthropomorphised. The central, green helmet in this drawing has a pair of ears. The irregular shapes and openings of the helmets suggest the organic properties of a skull rather than an inanimate, crafted object. The relationship between the delicate, spindly forms within and the solid casement is intimate and ambiguous. The helmets are firmly planted on solid ground since their weight is surely insupportable by the forms within. The two organisms are symbiotic, but they do not apparently connect with each other and Moore abandoned the traditional orientation of a helmet moulded around the wearer’s head. As Clark implied, the helmet-head motif was a synecdoche for the human body: although the motif isolates the head, it is a complete organism that does not register as a fragment. In the case of Helmet Head: Interior/Exterior Forms, the analogy to the human body is evident from the writhing, limb-like silhouettes of the helmets, which suggest the animation of limbs and torsos. Nevertheless, there is a tension between the interior and exterior components. The enclosure provided by the outer form is both protective and threatening, and there is a profound contrast between the apparent strength of the helmet and the vulnerable, open-bodied motifs within.

There are several possible sources of origin for Moore’s helmet forms. He visited the armoury at the Wallace Collection as a student at the Royal College of Art in 1921–24, and near the end of his life, speaking in 1980, he supposed that this experience unwittingly came to the surface in his helmet series: ‘the idea of one form inside another form may owe some of its incipient beginnings to my interest at one stage when I discovered armour. I spent many hours in the Wallace Collection, in London, looking at armour’. This connection inspired the Wallace Collection’s exhibition of the complete helmet head series in 2019, in which Helmet Head: Interior/Exterior Forms was included. The art historian and Moore specialist Julian Andrews, who worked at the British Council and collaboratively organised several exhibitions with the Henry Moore Foundation, argued that the helmet form bears some similarity to stahlhelm or ‘coal scuttle’ helmets used by the German army in the First World War. Such helmets have an uneven rim, which drops lower around the neck. Andrews wrote in 2006:

"more likely as an influence, surely, is the sculptor’s own direct experience of confrontation with helmets during the German counter-attack at Bourlon Wood Cambrai, on 30 November 1917, when the nineteen-year-old Moore was serving with the 15th battalion of the 47th (London) Division, the Civil Service Rifles. Helmet Head No.1 [LH 279] does, in fact, bear strong similarities to the classic German ‘coalscuttle’ helmet – Stahlhelm M16."

Helmet Head: Interior/Exterior Forms was first handled by the German Jewish art dealer Curt Valentin, who actively promoted and exhibited certain modern British artists at Buchholz Gallery, 32 East 52nd Street, New York. He has been described as ‘an important conduit of European modernism in postwar New York’. His selection placed a special emphasis on a perceived Neo-Romantic tendency that encompassed artists including Paul Nash, John Piper and Graham Sutherland. The decision to exhibit artists such as Moore, Ceri Richards and John Tunnard perhaps reflected the growing ascendancy of Surrealism in New York through the Second World War, which was caused by the forced emigration of artists and art dealers such as Valentin himself. Valentin held a solo exhibition of Moore’s work in 1943, Henry Moore: 40 Watercolors & Drawings (11 – 29 May), the artist’s first solo exhibition outside Britain. Buchholz Gallery held two further solo exhibitions of Moore’s work in 1951 and 1954, and it continued to display and to sell Moore’s work intermittently throughout its existence.