Mannerheim Line
/ˈmanəhʌɪm ˌlʌɪn/noun
A fortified defence line across the Karelian Isthmus, built in the 1930s to protect Finland from attack by Russia.
Origin
1930s; earliest use found in The Times. From the name of Baron Carl Gustaf Emil von Mannerheim, Finnish soldier and statesman, who built the line + line.