In October 1906 a deputation of Muslim notables met the Viceroy at Shimla and asked for separate electorates, seats reserved for Muslims and elected by Muslims only. The Morley-Minto reforms of 1909 granted it.
Sikhs asked for and obtained separate representation in Punjab from 1919. The Communal Award of 1932 fixed the shares for the province.
In a province that was roughly 53 per cent Muslim, 30 per cent Hindu and 15 per cent Sikh, separate electorates meant every politician answered to one community only. The Unionists were the one formation that tried to build across them and they did it despite the electoral system, not with it.
The census, the electorate and the reform movements between them turned overlapping and fluid religious practice into three hard blocs over about sixty years.
Whether separate electorates caused partition or only registered a division already forming is one of the standing arguments of Indian historiography, and Punjab is where the argument is tested because Punjab is where the price was paid.
The deputation was led by the Aga Khan and its thirty five members were landholders, titled men and lawyers rather than anyone elected by anybody. Whether the whole thing was got up with official encouragement, the command performance charge, has been argued ever since, and the papers of the men involved do not settle it either way.
Punjab was where that mattered most, because it was the province with no clear majority and three organised communities.
The Sikh claim to separate representation followed from the same logic and was granted later. Every subsequent argument about Punjab's politics runs through the categories set in those years.