Riesci a capire lo svedese antico del XIII secolo?

Yes, alot of it indeed. I used to live in Sweden and I was very surprised to hear some of the northern accents sounded more like icelandic than Norwegian or Danish. I still feel modern swedish and icelandic are more alike than icelandic and danish for example.

Yes, I can understand a large part of it. There are many words that sound a lot like the corresponding Icelandic word. Such as tolv (tólf), egh (ég), þiggia (þyggja), ganga (ganga), kunnung (konung), manna (manna), kombar (kemur), far (fer), þa (það) and olagha (ólöglegur).