Here is a thread showing some peaceful and voluntary dismantling of the British empire. 1/
en.m.wikipedia.org/wiki/Battles_o…
en.m.wikipedia.org/wiki/1929_Pale…
Coupled with Jewish insurgent campaigns by the Haganah, Irgun and outright terrorism by the Stern Gang
Though Gandhi himself led non-violent civil disobedience, the efforts to suppress independence on the part of the British authorities were not peaceful.
Also Subhas Chandra Bose led a violent anti-British movement during WW2
en.m.wikipedia.org/wiki/Indian_in…
(Ian Smith did not take kindly to it, declaring UDI and sparking a civil war against the ZANU and ZAPU movements)
en.m.wikipedia.org/wiki/History_o…
It was not dismantled peacefully & voluntarily. ENDS