 It is likely that these appointments were considered possible because the Irish Free State continued to recognise the British monarch as its official head of state . In 1937 , however , the Irish Free State adopted a new constitution , rendering the Crown 's position in Irish affairs ambiguous . The ambiguity was resolved 12 years later when the Irish Free State formally declared itself a republic and left the British Commonwealth . The basis for such appointments thus ceased and no further ones have been made . 
