Alright, so I think we can all agree that there's no perfect sword type, since all types of swords were designed for a specific duty and perform accordingly, so that it really rather depends on how it is used, and in what situation.

However, is there such a thing as a most lagom sword?

In other words, rather then being the best at everything, what sword could be said to be the most versatile and "jack of all trades", being capable of doing anything any other sword can do at least decently and get you by in most scenarios?

I'm going to go out on a limb and say any Oakeshott Type XVa. Some reach, some cut, some thrust. It's not a Swiss army sword, but it's pretty balanced.

Let's just keep in mind that this question is fundamentally misleading, since there is no sword that is great for every circumstance.

That having been said, I'd say that a Type XVI or XVIa is close. I would disagree about the Type XVa swords Gavin, because they're not as useful for cutting as a Type XVI(a). Really, the Type XV(a) and XVII are about as specialized thrusting swords as you can get in the Oakeshott typology. Both of them can still cut effectively, but an XVI will probably outperform them. Even so, you'll notice that a XVI(a) comes to a wickedly acute point. Sure, it may not be as narrow as a Type XV(a) or as rigid as a Type XVII, but this is a trade-off you make for having a blade that's a bit more cut-oriented.

I haven't spent much time playing around with the XVIII family at all, so they might be contenders too.

XVIa or XVIIIa, IMHO. But I agree that the question is misleading, because every attribute you stress detracts from other potential attributes that require different qualities. Perhaps a style or tactical situation calls for a specialized weapon. A well-rounded weapon wouldn't necessarily be an asset then. We have the benefit of choosing swords based on something other than survival, and being able to select from throughout history. I think that distorts our understanding somewhat.

If armour is factored out a type XIV like the Albion Sovereign would seem to me to be very capable of powerful cuts and very pointy for the thrust: Maybe not quite stiff enough against maille and too wide of point to be ideal finding chinks between plates in plate armour.

Helped along by a buckler it would be my choice for an everyday carry sword unarmoured. ( At least until I get my Doge in hand and get a feel for it's handling ).

All this based on cutting and thrusting versatility but style and skill of swordsmanship might make something like the A & A
Cavaliere Rapier a better option from 1540 to 1700 ( More a war sword in blade type than the more thrust biased narrow and barely or not at all sharp rapiers ).

Assuming that period anachronisms are permitted: A Sovereign styles type XIV blade bordering on a type XVI with a reinforced point combined with a Cavaliere rapier grip. :eek: :?: Anyway a lot of tweaking of such a design might be needed before I was pleased with it " functionally " but aesthetically it would be a fantasy piece: Just throwing this idea out there to stimulate discussion and it might be easy to convince me that there are better ideas. :p :lol:

I sort of understand the question although as the others have said it is a bit complicated. However in both Asia and Europe, just before gunpowder became a dominant factor on the battlefield I think in many ways sword design reached a highwater mark , and nowhere is this more evident (at least in my view) than with the "hand and a half" bastard swords of 15th century Europe, especially the Oakeshott type XVIIIs (a-e) and the XIXs (XVIs too). Good for on foot or on horse, with or without shield, cut and thrust, wielded with one hand or two. Many of the bastard swords of the 15th c. are just incredibly functional weapons. tr

Maybe a better way to consider the question might be which sword you would choose if you were facing an opponent(s) whose weapons and armor are a complete unknown. As has been stated this question has little practical bearing in an historical sense because in any given time period and region one could presumably make at least an educated guess at what one would face, but seen from a modern perspective it is a natural enough thing to wonder I think.
The most versatile sword I have I think is my Castellan, it could cut well enough against unarmored or very lightly armored foes and thrust as well as anything at mail and gaps in plate, and could be used with a shield or without, one hand or two.
Answering the question type by type seems kind of pointless since geometry and cutting/thrusting ability vary somewhat even among a single type or sub-type. I suspect that my Castellan could be made with a slightly wider, flatter section around the COP without sacrificing too much stiffness and have a bit more bite in the cut, but I don't think this would automatically put in into a different type since they are often defined by certain hilt types as well as blade characteristics.

I agree with those who have suggested swords that can be truly effectively wielded with one or two hands. One handed capability is required in case you needed to employ additional protection in the form of a shield or even use a secondary weapon such as a dagger. Two handed capability is required to maximise power and/or speed and/or accurracy for thrusting attacks, half swording,cutting and recovery. It is a given that the sword would have to be capable of thrusting in case the opponent was heavily protected. It is also a given that the sword would have to be responsive enough for unarmoured situations. A smaller XVa, XVIIIb or XVIIIc that can be effectively wielded in one hand may fit the bill, with an emphasis slightly towards the cut. Either that or a XVIa with a geometry that more aligned to the thrust than is normal (if there is such a thing) for the type.

Either way it would have to be one of the true cut and thrust types (I know that XVa's are considered thrusting swords but there are enough examples out there that can also cut very well), and if was it was a type that is recognised as being more aligned to the thrust then it would have to be tweaked to accommodate it ability to cut more, and the opposite would apply to a type that is more aligned to the cut. Either way the sword would be a compromise on it's historical type in an attempt to make it more versatile.