Detach (move) subdirectory into separate Git repository

I have a Git repository which contains a number of subdirectories. Now I have found that one of the subdirectories is unrelated to the other and should be detached to a separate repository. How can I do this while keeping the history of the files within the subdirectory? I guess I could make a clone and remove the unwanted parts of each clone, but I suppose this would give me the complete tree whe

[nharuki]

「ごった煮リポジトリから特定のディレクトリ下だけ履歴込みで分離させたいときはどうすればええんや？」→「それ git subtreeでできるで！！」

[Yuryu]

git subtree の使い方。べんり。

[saiten]

gitリポジトリの分割

[kbkbkbkb1]

リポジトリの分離法

[fumikony]

リポジトリを分割する

[a_bicky]

Gitリポジトリの分割方法

[craccho]

gitリポジトリの分割法

[jimo1001]

リポジトリを分割

[mickn]

Git のリポジトリの分割はこの手順でいいのかな

[akkun_choi]

リポジトリ分割