I mean a kind of party which guests and hosts hide their faces behind different masks or/and wear odd clothes. Surely there is no certain idea about main concept with me unless perhaps it has roots in customs and traditions or religions like Halloween religious roots.
The answer appears to be the Venetian Republic was the first nation to hold masquerade balls.
Victorian Masquerade Ball confirms many of the assertions in wikipedia
Samantha Peach has an article that is less well sourced