This is the first time that the Scottish Parliament, the National Assembly for Wales and the Northern Ireland Assembly have together refused consent for a UK bill.
Most striking is the extent to which, just days after Stormont reopened for business, the normally divided parties and communities united to express their opposition.
Each legislature shared concerns that the Bill gives UK ministers powers to make decisions in devolved areas without their agreement.
They also share frustration that the devolved institutions are being side-lined in the Brexit process, and fear that legislative preparations for Brexit are eroding devolved powers.
The withholding of consent by devolved legislatures was never going to stop the bill from being passed. There is no devolution veto.
Under each of the devolution settlements, external relations and treaty-making are responsibilities of the UK parliament. Plus, the UK parliament is sovereign. It can make or unmake any laws, including in devolved areas.