The blade inscription is a slightly shorter version of 'SIGVINAIS', which has been interpreted as S(alvator) I(esu) G(enitrix) V(irgo). I(esus). N(omine) A(ltissimi) I(esu). S(alvator). See D. A. Drboglav Zagadki Latinskikh Kleim na Mechakh IX-XIV vekov, 1984, p.118.
This sword, the hilt decoration in particular, compares closely with the so-called 'River Witham' sword in the British Museum (1848,10-211), dating from the late 9th century and classified as Petersen type L variant. Further comparison identifies the present sword as an example of the 'Wallingford Bridge' type dating from the 10th -11th century, a further variant of the Petersen type L.
It is suggested that the hilt fittings were probably made in a Southern English, late Saxon, workshop.
See Ian Peirce, Swords of the Viking Age, Woodbridge 2002, pp.77-79.