The 'Wheel (realm) of the Law', is a name for the doctrine 'set rolling' (established) by the Buddha, i.e. the 4 Noble Truths (sacca, q.v.).

"The Perfect One, o monks, the Holy One, fully Enlightened One, in the Deer Park at Isipatana near Benares, has set rolling (established) the unsurpassed Wheel (realm) of the Law" (M. 141). Cf. cakka.