English: Simla Convention borders in Kham (Hugh Richardson, 1945). The map shows

• the frontier of Tibet (in red), and
• the boundary between the Lhasa-controlled 'Outer Tibet' and Chinese-administered 'Inner Tibet' (in blue)

as decided at the 1914 Simla Conference. Tibet and Britain signed the Convention, but not China.

The southern portion of the red line up to the Isu Razi pass formed the boundary between Tibet and British Raj, later coming to be called the McMahon Line.