The University of Iceland offers two international graduate programs in medieval studies:

(1) Medieval Icelandic Studies, a three-semester (90 ECTS) graduate program, with two semesters' (60 ECTS) worth of course work and one semester's worth (30 ECTS) master's thesis. The summer semester is the thesis semester, which means that the program can be completed in 13 months. 

See http://english.hi.is/school_of_humanities/faculty_of_icelandic_and_comparative_cultural_studies/medieval_icelandic

(2) Viking and Medieval Norse Studies, a four-semester (120 ECTS) graduate program run in cooperation with the University of Oslo in Norway, Aarhus University and Copenhagen University in Denmark. The first year--60 ECTS' worth of course work--take place in Iceland, but the third semester is spent either in Oslo, Aarhus, or Copenhagen, completing 30 ECTS of courses. The fourth semester is devoted to writing the master's thesis, and can be spent in Iceland or Oslo.

See http://oldnorse.is/

Both programs are designed specifically for international students. The language of instruction is English.