copper and iron swords were easier to make but less durable while bronze and steel swords were more effective for combat but more difficult to fashion.
Explanation:
Pros
Copper: It was a very common material and it could be sharpened easily.
Iron: Like copper, very easy to find and harder than copper, so it is a better option to fabricate iron swords than copper swords.
Bronze: Bronze is harder than copper and its rust is just shallow which make bronze swords way durable in comparison. With the materials in hand (copper and tin), it was easy to fabricate bronze swords on a great scale.
Steel: This is the most durable and hardest of all the elements above.
Cons
Copper: Easy to get rusty and be broken.
Iron: Sucseptible to severe oxidation, although it is more durable than copper.
Bronze: As this is an alloy, it requires copper and tin, which it is not very common to find close each other, so it makes difficult to make bronze swords. Additionally, bronze weapons do not last very much; they are easy to break.
Steel: Unlike bronze, steel rusting can wreck the sword if it is treated in time. Additionally, on ancient times, steel forges were very uncommon as not many knew the way to create steel from iron and carbon, so steel swords were very expensive and more likely to find in hand of kings and royal guards.
Pure metals are generally soft ones. However, when added with another kind of metal, the alloy now forms into a stronger substance. This is the reason why alloys are used in making swords. Metals are easier to find at that era and because of their lustrous and can be sharpened, metals are precurors of swords.
I mean... Eventually some kings left the Papal authority. However, remember the crusades? It united nearly everyone in Europe. Some to the point of making new states.
