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Antoninus Pius Dupondius, 152-153 AD. 11.1 gr.

Obv: ANTONINVS AVG PIVS P P TR P XVII, radiate head right.
Rev: LIBERTAS COS IIII, S-C, Libertas standing right, holding 
pileus and extending hand. 

RIC III, 920; Walker 6-7. 

Note: David Walker, in his "Bath Report" is of the opinion
that this coin is part of an issue that was apparently struck
in Rome especially for use in Britain. Walker calls this and
other coins of the same period "coins of the British
Association". Eleven coins of this type were found in the 
Sacred Spring at Bath.