Those Broaches tested so far belong to Haplogroup I1 (a combination of DNA sequences at different places on the chromosome  that are transmitted together) that share a common ancestor with a single nucleotide polymorphism (SNP) mutation.  It is estimated to be 4,000 to 5l000 years old & is confirmed by the SNP known as M253. 

While many I1 members trace their ancestry to Scandinavia, others find their roots in the British Isles, Germany & beyond.

To read more, go to:

Family Tree DNA:  http://www.familytreedna.com/public/yDNA_I1/default.aspx

Wikipedia:   http://en.wikipedia.org/wiki/Haplogroup_I1_%28Y-DNA%29