We know about Mimming because plays an important part in the story of Waldere. Unfortunately, only a fragment survives, but luckily, that fragment is about the sword. We can put the fragment in context by referring to another early poem: Waltharius, written in Latin by Ekkehard of Gall in the early 10th c. I put these two together to write a full account of Waldere's story, and the sword, Mimming. The following extract is the chapter from Book II of English Dawn, Warrior:

Mimming was reputed to have been made by the legendary smith, Weland. In practice it would have been a typical, pattern-welded sword of the Nordic dark ages. A smith would twist together rods of red-hot iron and hammer them into shape, making a sword that was both tough and flexible. However, Mimming can't have been that good because it shattered on Hagen's helmet. Later in my pentalogy, I have a smith called Brom, reforging the blade with rods of Damascus steel. 

My first version of the full story, combining Waldere and Waltharius was in a book entitled Waldere (2012). I wrote it in a modern version of the Anglo-Saxon poetic line (four stresses, with a flexible number of unstressed syllables, in two half lines, with alliteration to join the half lines. It wasn't easy! As with rhyme, trying to get the alliteration can lead you into writing rubbish. Below as the version in English Morn, a companion to English Dawn, which tells the same story in verse:

There are more famous swords in the pentalogy: Hildeleoman is the sword used by Hengest to slay King Finn, Tyrfing is the name Hrothwyn gives to her seax in honour of her shieldmaiden heroine, Hervor and, in the last chapters of the pentalogy, the Sword of Albion, Excalibur, is thrust into a stone by Merlin in preparation for the king who is to come. I will post extracts about these swords in future updates.