Twenty-three radiocarbon results are now available from the Wayland's Smithy long barrow, and are presented within an interpretive Bayesian statistical framework. Four alternative archaeological interpretations of the sequence are considered, each with a separate Bayesian model, though only two are presented in detail. The differences are based on different readings of the sequence of Wayland's Smithy II. In our preferred interpretation of the sequence, the primary mortuary structure was some kind of lidded wooden box, accessible for deposition over a period of time, and then closed by the mound of Wayland's Smithy I; Wayland's Smithy II was a unitary construction, with transepted chambers, secondary kerb and secondary ditches all constructed together. In the Bayesian model for this interpretation, deposition began in the earlier thirty-sixth century cal. bc, and probably lasted for a generation. A gap of probably 40–100 years ensued, before the first small mound was constructed in 3520–3470 cal. bc. After another gap, probably of only 1–35 years, the second phase of the monument was probably constructed in the middle to later part of the thirty-fifth century cal. bc (3460–3400 cal. bc), and its use probably extended to the middle decades of the thirty-fourth century cal. bc. Results are discussed in relation to the local setting, the nature of mortuary rites and the creation of tradition.