For pre-(widespread)firearm warfare? A warhammer, duh. Two-handed if you're wearing full plate, one-handed if not (in the other hand, use a shield). If you're not wearing armor, and for some reason are forbidden carrying a shield with your warhammer, just take the shield. Still can bludgeon, and defense is more important.
If you are the cavalry, then a flail. Still deadly, and you don't have to worry about the recoil, which would be a concern otherwise when you have the speed and mass of your horse backing up your swing.
If it were allowed, I'd say Bec de Corbin. Polearm, has a hammer, a stabby stabby blade, and a pick for concentrated force. Great anti-armor weapon.
For civilian usage? A cane. Don't have to deal with laws restricting weaponry, you can carry it anywhere, it can aid walking and hiking, and can be stylish if you use a discerning eye when picking one.
And for mammoth hunting? Fuck clubs, fuck bludgeoning, that won't do shit, spear/javelin all the way. We've been making spears for forever, we hunted mammoths with spears, don't even try to push that club bullshit, those lies. Spears, and traps. And the spears were generally thrown. Sometimes via an atlatl.