These seemed to have developed out of the ubiquitous bollock dagger and are found in Northern England and Scotland.
The Dudgeon is a transition between the bollock dagger and the dirk and was around in the late 16th and early 17thC.
By the mid 17thC. the form had developed into the dirk and by the 18th C many were carved with the distinctive knotwork handles.
Plain Dirk from £300.
Dudgeon from £250.