Republic or monarchy

The earliest Westminster Model constitutions – those of Australia, Canada, New Zealand and South Africa – took unambiguously monarchical forms. Executive power was vested in the Crown, which was also an integral part of the legislature. Even in the post-war era, many former colonies, on becoming independent from the British Empire, did not cease to be part of ‘Her Majesty's dominions’. They continued as ‘Commonwealth realms’, with the functions of the Head of State being performed by a Governor-General nominally appointed by the Queen.

The Irish Free State was a more difficult case to classify. The characteristic ‘dominion-style’ provisions of the 1922 constitution, which were included to satisfy the terms of the Anglo-Irish treaty, were whittled away by successive amendments. The new Irish constitution adopted in 1937 established a popularly elected president as de facto Head of State. Yet it formally retained at least a vestigial link to the Crown, through the Executive Authority (External Relations) Act 1936; this strange arrangement persisted until 1949, when the Republic of Ireland Act 1948 came into effect.

Although the powers and privileges of the Crown could be determined by each dominion through its own constitutional processes, Commonwealth membership at the time entailed a common allegiance to the Crown. By becoming a republic and ceasing to be part of His Majesty's dominions, Ireland – like Burma two years earlier – thereby ceased to be part of the Commonwealth.

Despite this change in status, both Ireland and Burma retained Westminster Model constitutions in republican guise, with a ceremonial figurehead president taking over the functions that elsewhere would normally be performed by a Governor-General. The separation between what Walter Bagehot called the ‘dignified’ (ceremonial) and ‘efficient’ (governing) parts of the constitution, and the relegation of the Head of State to primarily symbolic and civic functions, makes the identity of the Head of State a secondary matter.

In April 1949 – too late for Ireland – the rule binding Commonwealth membership to allegiance to the Crown was relaxed, by means of the London Declaration.