'Valentine' (iii) was the Chinese advance of General Wei Li-huang’s 'Y' Force (Chinese Yunnan Expeditionary Forces) from Yunnan in southern China into the northern part of Japanese-occupied Burma (11 May 1943/27 January 1944).
The 'Y' Force comprised more than 100,000 Chinese Nationalist troops allocated to General Li Pin-hsien’s 11th Army Group and the 21st Army Group, and became involved in major ground operations in support of the offensive of Lieutenant General Joseph W. Stilwell’s Northern Combat Area Command in northern Burma. Unlike many of his contemporaries, Wei Li-huang was able to work effectively with US commanders.
Beginning its offensive into southern Yunnan on 11 May 1944, the 20th Army Group of 'Y' Force took Tengchung on 15 September after two months of heavy fighting. In a parallel movement farther to the south, on a south-westerly axis and in the face of strong resistance by Lieutenant General Yuzo Matsuyama’s 56th Division of Lieutenant General Masaki Honda’s 33rd Army, the 11th Army Group eventually linked with the Chinese New 30th Division of Lieutenant General Sun Li-jen’s Chinese New 1st Army of the Northern Combat Area Command in the Burmese town of Wanting on 27 January 1945.
The success of this offensive allowed the Allies to reopen the former Burma Road supply network to China through Ledo and now renamed as the Ledo Road. In concert with existing airlift operations over the 'Hump', the opening of the Ledo Road made possible overland transport of military supplies from India to the Chinese Nationalist bases in southern China.