This is an example of a ball-type penannular brooch, which would have functioned as a dress or cloak fastener. The type originated in the native Irish tradition during the second half of the ninth century. Its fabrication in silver was made possible for the first time by the introduction of large quantities of this precious metal into Ireland by the Vikings. Early examples of ball-type brooches, such as this one, exhibit solid globular terminals with criss-cross brambles decoration and are consequently often referred to as a thistle brooch. They occur quite commonly as single finds in Ireland, particularly in the midlands and the south, such as the one that was found with the famous chalice at Ardagh, County Limerick.
Scandinavians who had travelled to Ireland used these brooches and took examples home with them, and by the tenth century, a variant type (with large hollow-cast terminals) was being produced in Scandinavia as well as in settlements in the Irish Sea region. Examples of this and of further variant types have been found in Ireland and Scandinavia, as well as Britain and Russia. It has been suggested, presumably on the basis of its small size, that this brooch is a nineteenth-century reproduction. However, the details of its manufacture and the slightly misshapen state of its pin do not support such speculation.