Etymology and distribution of 公下.

The Japanese surnames etymology dictionary.
https://play.google.com/store/apps/details?id=info.jigensha.jcedfreeGoogle Play で手に入れよう https://apps.apple.com/us/app/id1471109324
↑オフライン検索できるアプリもどうぞ

Popuration of 公下.

カンマ区切りで複数の名字を指定できます。

Etymology of 公下

Distribution of 公下
Ranking
1 Ishikawa-ken(About 30)
2 Oosaka-fu(About 10)
3 Mie-ken(Very rare)
3 Kyouto-fu(Very rare)
3 Hyougo-ken(Very rare)
3 Nara-ken(Very rare)
3 Miyagi-ken(Very rare)
3 Iwate-ken(Very rare)
3 Kanagawa-ken(Very rare)