Mike Thomson returns with Radio 4's investigative history series. He visits Dublin to examine what new documents reveal about Britain's role at the start of the Irish Civil War.

Mike Thomson returns with Radio 4's investigative history series.

Dublin 1922. Irish rebel leader Michael Collins has signed a new Treaty with Britain. The new Irish Free State is taking shape.

But even as Collins was establishing the Free State, a rebellion from within Irish Republican ranks broke out against the new state and the Treaty with Britain. The anti-Treaty forces seized the 'Four Courts' legal complex in central Dublin.

Meanwhile, in London, the former Chief of the Imperial General Staff, Sir Henry Wilson, was assassinated by Republicans outside his Chelsea home.

The British Government urged Michael Collins their recent foe - and now fellow national leader - to act.

Mike visits Dublin to examine what a soldier's forgotten memoir reveals about Britain's true role at the start of the Irish Civil War.

Producer: Neil McCarthy.