MPs took the unprecedented step of voting to seize control of the parliamentary timetable [...] --BBC
Is this speaking hyperbolically, or is it really the case that it never happened before in the history of the House?
After a bit more digging, basically the (claimed) unprecedented event was the one-day suspension (by Letwin's motion) of Standing Order 14, more precisely
(a) Standing Order No. 14(1) (which provides that government business shall have precedence at every sitting save as provided in that order) shall not apply on Wednesday 27 March;
So basically we can ask more specifically if Oder 14 was never suspended in its (100+ years) history. Because the allocation of time was otherwise somewhat modified in the 2010 reform:
Some of these reforms were put into action: the Backbench Business Committee was established, and is responsible for choosing subjects for the 35 days’ of backbench time each session. But the House Business Committee idea ultimately did not get off the ground. Despite the Commons endorsing the idea in 2010, and the Coalition Government committing to its establishment, the then-government dropped the plan in 2013. It claimed that they couldn’t find a consensus on how the new system would work in practice—and no subsequent government has seen fit to resurrect the idea.