Ancalagon
Dusty Dragon
And that's just the baron.
The Duke who is 3-5 ranks higher than the baron would have knights in +2 plate armor +1 shields, with +1 lances and +2 swords, a ranger or druid with +1 staff and +1 bow guarding the ducal woods, a church appointed priest who can cast cleric spells and has a common relic, and a personal academic who might be pulled into employment via access to a common arcane item if they aren't a caster themselves.
The way I see it, a knight or baron could have a +1 sword, a count or marquis a +2 one, a duke, prince or minor king +3, and then a king of a substantial kingdom problably has a legendary sword, that is considered part of the "regalia" of the king and is transmitted from generation to generation. A powerful sword owned by a powerful king, one that his great great great grandfather used to slay a dragon? Yeah, that's legendary all right

One thing that can be a problem is that if the PCs fight a lot of foes that would "make sense" to have magical items, they soon would have a lot of magical loot. I believe this is why most monsters do not have "grab-able" magical items.This is one of my big issues with the Monster Manual.
Some entries in the Monster Manual should have options for Magically equipped versions of themselves.