An important and rare jadeite double-square seal. Incised Jiaqing Chen Han and Ji Xia Yi Qing marks and probably of the period. Photo Bonhams

The seal carved from one piece of jadeite as two rectangular columns of square section joined at the top with an arched finial, carved in relief on the first seal surface with the characters Jiaqing Chen Han and incised on the second seal surface with Jixia Yiqing; together with a fan belonging to William Lockhart printed on one side with a map of China and on the other with a map of Beijing pointing out the location of Lockhart's hospital in Beijing marked with an x. Each seal surface 2cm (¾in) square, both seals overall 3.1cm (1¼in) high x 4.3cm (1¾in) wide x 2cm (¾in) wide (2). Estimate: £40,000 - 60,000, HKD 510,000 - 760,000, $ 65,000 - 98,000

Provenance: the old label attached to the seal reads: A Seal of Kia Ching from Yuen Ming yuen

William Lockhart (1811-1896), F.R.C.S. F.R.G.S., of the London Missionary Society, and thence by descent to the present owner.

The seal inscriptions reading Jiaqing Chen Han (Jiaqing Emperor's Literary and Artistic Work) and Ji Xia Yi Qing (When does one have the leisure to delight the heart?), have been used during the Qianlong period, with paintings extant with the seal impression Qianlong Chen Han; see a painting sold at Christie's Hong Kong, 1 December 2010, lot 2832; see also an Imperial tianhuang seal carved with the inscription Qianlong Chen Han, sold at Sotheby's Paris, 11 June 2009, lot 249; and an Imperial inkcake of the Qianlong period impressed Yo mo Zige Mingxun and with one seal of the Qianlong Emperor, Jixia yiqing, sold at Sotheby's Hong Kong, on 8 October 2009, lot 1812. The seal Jixia yiqing is recorded by Victoria Contag and Wang Chi-Ch'ien, Seals of Chinese Painters and Collectors, Hong Kong, 1966, pp.586 and 593, no.71, as one of Qianlong's seals.

The Jiaqing Emperor adopted the inscription Chen Han on one of his own seals. According to Guo Fuxiang, Researcher, The Palace Museum, Department of Palace History, Beijing, Jiaqing Chen Han, importantly, is recorded as one of the inscriptions used by the Jiaqing emperor; see Guo Fuxiang, Two Jadeite Seals Belonging to the Jiaqing Emperor, An Important Private Collection of Qing Historical Works of Art, Sotheby's Hong Kong, 7 October 2010, p.18.

William Lockhart was born on 3 October 1811 in Liverpool. He trained at the Meath Hospital, Dublin, and Guy's Hospital, London. Joining the London Missionary Society, he was appointed medical missionary to Canton and sailed on 31 July 1838. In 1839 he left Canton to set up a hospital in Macao. Following an arrangement with American missionaries he left Macao for Chusan and reached Tinghae on 13 September 1840. The following year he returned to Macao and married Catherine Parkes. In 1842 he went to Hong Kong, then to Chusan, and in 1843 arrived at Shanghai and opened a hospital with Dr. Medhurst.

Following a trip home to England, Lockhart visited Beijing and worked there from 1861 to 1864. He returned to England permanently in 1864 and retired in 1867. He was elected Chairman of the Board of Directors of the London Missionary Society from 1869 to 1870. In 1892 he presented his library to the London Missionary Society. He died on 29 April 1896.

In 1860, during the Second Opium War, British and French expeditionary forces, having marched inland from the coast, reached Beijing. On September 29, two envoys, Henry Loch and Harry Parkes went ahead of the main force under a flag of truce to negotiate with the Prince I at Tongzhou. After a day of talks, they and their small escort of British and Indian troopers (including two British envoys and a journalist for The Times) were taken prisoner. They were taken to the Board of Punishments in Beijing where they were confined and tortured. Parkes and Loch were returned after two weeks, with fourteen other survivors. Twenty British, French and Indian captives died. On the night of October 6, French units diverted from the main attack force towards the Old Summer Palace.

In 1861 Lockhart published The Medical Missionary in China: A Narrative of Twenty Years' Experience, London, 1861. In this book, p.374, following the description of the Loch and Parkes peace mission, he notes the following, providing us with a rare insight into the British attitude at the time:

'On its being known that such cruelty had been inflicted on the victims of this treachery, and that the remaining captives were not given up, immediate steps were taken for the capture of Pekin, and finally one of the gates was surrendered to the allies. The city thus lay at the mercy of its captors without any further hostilities. The palace of the Yuen-ming-yuen was burned and destroyed by the English General on the 16th of October, as a punishment to the government for the perfidious cruelty towards the prisoners, and more especially as it was in that place that the barbarous treatment towards them commenced. This was one of the last acts of the expedition. It was wholly warranted by the occasion, and signally marks the indignation of the army against those who entrapped persons into their hands, and then cruelly tortured them to death. A money compensation was also demanded, on account both of the survivors and the relatives of those who had died.'

The provenance of the present seal, the presence of the missionary Lockhart in Beijing certainly in 1861 and possibly during the sacking of the Yuanming Yuan by the Anglo-French forces, and his unequivocal support of the actions taken by the English, is important evidence in support of the present seal's Imperial origin.

Bonhams. Fine Chinese Art, 12 May 2011, New Bond Street