Located in modern-day Portas do Cerco, the Macao Peninsula was connected to Xiangshan Island by a narrow isthmus about 100 m (330 ft) wide and 1.2 km (0.75 mi) long.

[6] On 6 August 1840, Chinese soldiers kidnapped Reverend Vincent Stanton while he was swimming at Casilha Bay in Macao, causing an uproar in the British community.

[7][8] On 18 August 1840, the steamer Enterprise, HMS Druid, and the transport ship Nazareth Shah, which had a detachment of Bengal Volunteers on board, arrived off Macao.

[9] The Hyacinth and Larne, accompanied by the cutter Louisa and Enterprise, having seamen and marines of the Druid with Bengal Volunteers on board, attacked the barrier.

[13] The Chinese restored their defences a year later when they built the Latashi fort, one kilometre north of the Barrier Gate.