Subeg Singh was a contractor and a government official at Lahore, respected enough to be used as an intermediary between the administration and the Khalsa, and it was he who carried the offer of the Nawabship to the Sikhs in 1733.
In 1745 he and his son Shahbaz Singh, a student of about eighteen, were arrested. The son had been studying with a qazi who wanted him to convert. Both refused.
They were executed on the charkhri, the wheel, a device with spokes to which a body was bound and broken.
The manner of it is depicted in the Sikh Museum at Amritsar and named in the middle section of the Ardas, where those who were broken on the wheel are remembered daily.
A senior government contractor and his teenage son, killed for refusing conversion, is a case that shows the persecution reaching into the administration's own establishment.
The Nawabship offer he carried in 1733 was an attempt to buy peace with a title and a jagir. The Khalsa assembly debated whether to take it and accepted it in the name of the whole body rather than of any man.
The charkhri was a public execution and was used at Lahore in this period on more than one occasion. It is one of the specific methods the Ardas names, alongside being sawn and being scalped, which is how the vocabulary of that decade entered a daily prayer.
The charge was association with the Sikhs. Those broken on the wheel are named as a category in the Ardas, and these two are the case the phrase is usually attached to.