Final answer:
The Statute of Westminster in 1931 granted autonomy to the dominions of the British Empire, leading to their legislative independence and signifying a major step in the decline of British imperial power and the rise of self-governance for these nations.
Step-by-step explanation:
The Statute of Westminster, passed in 1931, was a pivotal change brought about by the United Kingdom Parliament which effectively granted full autonomy to the dominions of the British Empire. This included countries such as Canada, Australia, New Zealand, South Africa, the Irish Free State and Newfoundland. Before the statute, these dominions had been ruled to some degree by the British government. By enacting the statute, the UK government granted these dominions legislative independence, marking a significant step in the development of their national sovereignty and the decline of the British Empire.
The statute can be seen as part of a broader process of constitutional change that had begun with earlier events such as the Glorious Revolution, which asserted Parliament's authority over the monarchy, and the Great Reform Bill of 1832, which expanded the electorate and addressed parliamentary reform. It also followed the pattern of slow and steady liberalization of British politics through the 19th century. Most notably, it reflected the principle that 'each province was to rotate on its axis, but all of them were to revolve around England as the center of the imperial system' similar to the arrangement that had been found after the tensions in the Dominion of New England during the reign of William and Mary, though on a much larger, empire-wide scale. Ultimately, the Statute of Westminster represented an important milestone in the evolution of the Commonwealth nations towards full self-governance.