 While bishop, Farnham continued to work for the king.In 1241 he was mediating with King Alexander II of Scotland, and in 1242 he was involved in the negotiations over the marriage of King Henry's daughter Margaret to the future Alexander III of Scotland.As a bishop, he became embroiled in a dispute with a dependency of St Alban's Priory, which was finally settled in 1248 in the priory's favour.