First, it was the only constitution in the British Empire (outside Dominions of Australia, South Africa and Canada) enabling general elections with adult universal suffrage.
For the first time, a "dependent", non-caucasian country within the empires of Western Europe was given one-person, one-vote and the power to control domestic affairs.
Power and funding followed those with the ability to maximise broadbased multi-ethnic support: negotiators and peacemakers were therefore elevated above demagogues and warmongers.
The Donoughmore Commissioners had been appointed by the socialist Sydney Webb, who was briefly Secretary of State for the Colonies in the Labour minority government of 1929-31.
He appointed Commissioners who he knew shared his desire for an equitable and socialist British Empire and they in turn came up with a constitutional arrangement for Sri Lanka, which would ensure that every community in the island had a chance of for power and prosperity.