dhamma-cakka: 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.

Buddhist Dictionary, Manual of Buddhist Terms and Doctrines, by NYANATILOKA MAHATHERA