A newbie question about fortress defending

[Chazar]

I thought that I have read somewhere here in this forum (but never tested), that at least one unit (regardless of commander status) is required to have siege...???

[archaeolept]

huh? my post got lost.

basically, i believe chazar is correct, since in a recent game one sieging tartarian immediately breached the walls of my undefended dark citadel. This should not have been possible w/out some special "undefended castles are immediately breached" rule.

[Cainehill]

Yep, you want/need at least 1 unit there defending - it can be a commander, or a militia man, but without it the castle can basically be walked into by the enemy.