Bayesian modelling with the development of Markov Chain Monte Carlo samplers has made rapid progress in recent years. The models that can now be fitted by existing software has seen a considerable expansion in the complexity of the problems that can be tackled. This day consists of 4 linked sessions that introduce and showcase recent developments in this area. It is convened by the LEMMA and BIAS nodes of the ESRC National Centre for Research methods in collaboration with the Quantitative Methods Research Group.