I read it in Russian, it is called "The Horse of knyaz Vytautas". The plot is basically that one winter was particularly snowy and lake Galve was about to flood karaims farm fields. So karaims sent delegation to knyaz to ask for advise and there was a bit of hesitation whether or not to include women in the delegation since (literally) "женщин впускать в замок было запрещено под угрозой смертной казни." The solution knyaz found was very efficient albeit quite fantastic - he let his horse drink water until the threat of flooding subsided
Did that really happen, and if so, what was the reason for the ban?