While in verb-initial Old Irish, topicalization was achieved via left dislocation and focalization was achieved through clefting, the older Continental Celtic languages achieved such pragmatic information structuring through movement into the left periphery of the clause (though the right edge of the clause could also be a target for such purpose).  This paper commences with an inspection of relative clause syntax in Continental Celtic while outlining what we can tell about other movement mechanisms in the clause and then goes on to explore the architecture of the left periphery in these languages.  This exploration provides some insight into the prehistoric development of verb-initial clausal configuration in Insular Celtic.  Some comparative attention is also paid to the architecture of the left periphery in other Indo-European languages and it is found that the Continental Celtic languages have a role to play in determining the degree of articulation to be reconstructed for the left periphery of proto-Indo-European itself.