Lei is only one of several names given to vessels of this shape. A variety of designations, including lei, ling, fou and pou, appear in inscriptions cast on the everted rims of some of these bronzes, even vessels closely comparable in shape. This vessel type first appeared in the late Shang/early Western Zhou period, and early versions typically had a long neck and sharply angled shoulders. By the end of the eighth century, the necks on these vessels had become proportionately shorter, and the shoulders more rounded. With its sharply angled shoulders and short neck, the present lei would appear to represent a transitional period in the vessel's development.
A lei of very similar shape, and with identical decoration, but with the addition of handles, from the collection of Dr. and Mrs. P. H. Plesch, was sold at Christie's New York, 16 September 1999, lot 251. (Fig. 1) J. So, in Eastern Zhou Ritual Bronzes from the Arthur M. Sackler Collections, Arthur M. Sackler Foundation, 1995, illustrates a fou, pp. 206-9, no. 31, which is decorated with variant dragon bands, which also have low-relief S-shaped dragons with a head at each end and raised bosses for eyes and body junction. The dragons, however, are stylistically a bit different, as are those on a lei and two fou from the Worcester Art Museum, Shangdong Ju Xian Tainjingwang, and Brundage Collection, Asian Art Museum, San Francisco, illustrated ibid., figs. 31.1, 31.2 and 31.3 respectively. The dragons on the Shangdong Ju Xian Tianjingwang example, which is dated to the early 7th century BC, are most similar to those on the present jar, although the shape of that vessel is more rounded and squat, and the width of the bands is more varied. Other comparable lei include one dated Middle Zhou dynasty, 7th century BC, illustrated by J.A. Pope et al., The Freer Chinese Bronzes, vol. I, Washington, 1967, pl. 84 (Fig. 2); one illustrated by B. Karlgren in A Catalogue of the Chinese Bronzes in the Alfred F. Pillsbury Collection, Minneapolis, 1952, p. 141, pl. 72, no. 52; and one sold at Christie's New York, 22-23 March 2012, lot 1532.
Unlike all of the aforementioned comparable vessels, which feature either a pair of handles, and in one case four handles (Pillsbury), the present lei is highly unusual in that it lacks handles. Another lei without handles and with related dragon scroll cast on the shoulder, but undecorated on the lower body, from Henan Xinyang Guangshan Baoxiangsi G1, is illustrated by J. So, ibid., p. 134, fig. 13.2, where it is dated to the second quarter of the 6th century BC.