In October 1921 the Deputy Commissioner of Amritsar took possession of the keys of the toshakhana of the Golden Temple, the treasury holding the shrine's valuables, and handed them to a government-appointed manager rather than to the SGPC.
The Akalis treated this as the government asserting control over the central Sikh shrine. A campaign of protest and arrest followed. Around 150 leaders were jailed, including Baba Kharak Singh.
In January 1922 the government gave way. The keys were returned in open assembly to Baba Kharak Singh.
Gandhi sent a telegram calling it the first decisive battle for India's freedom won. The phrase is quoted constantly in Punjab and rarely elsewhere.
The episode established that the SGPC, an elected Sikh body, held the shrines. Everything about Sikh institutional politics since runs through that.
The government's stated position was that it was protecting the property while a management dispute ran. That framing collapsed once the arrests began, because a custody question does not require a hundred and fifty arrests.
The agitation that followed filled the jails and was conducted without violence, which was the Akali method throughout this period. The government's retreat came when the arrests became politically unsustainable.
The Sikh Gurdwaras Act followed three years later and put the shrines under an elected committee by statute. This is the point at which that outcome became inevitable.