The question of whether Mars could have supported life has driven intensive exploration of the planet's surface through satellite and robotic missions. Complementary research has focused on identifying and understanding meteorites from Mars, which offer the only direct samples of the crust available to science. Together, these studies have not only sought signs of extraterrestrial life and habitable environments, but tried to understand how the planet has changed through time: from an ancient world of oceans and landforms remarkably familiar to Earth, to the cold, dry, barren planet that we see today. Why Mars has followed a dramatically different path to Earth is a major issue in our understanding of terrestrial planet evolution. How has Mars lost heat? Has volcanism and volcanic outgassing changed through time? Is volcanism and seismic activity ongoing? How has impact cratering shaped the planet through time? It has become clear that much of the surface of Mars is very ancient, and that its rocks retain direct evidence of the planet's separation into a crust and mantle. As a result, volcanism is thought to be driven by mantle plumes, rather by tectonic forces at plate boundaries as on Earth, and to have reduced rapidly in intensity to a minimum as the planet has cooled. This relatively simple geological model compared to the Earth suggests declining rates of exchange between the surface, atmosphere and interior through time, including the cycling of potential nutrients, heat loss and volcanism. This view has been challenged by recent evidence for considerable diversity in volcanic and sedimentary rocks and processes on Mars. However, new understanding of the planet is hindered by a mismatch between Martian meteorites and rock types seen on the surface, as well as a lack of reliable age information that can be used to test how the crust, mantle and atmosphere have evolved and interacted through time. Addressing these issues is a primary aim of ongoing and new Mars exploration missions, including NASA InSight and Mars 2020 and the ESA ExoMars Rover, and also requires resolution of conundrums in the Martian meteorite collection. The UoP2 Mars Consortium brings together internationally leading expertise in Martian meteorites, radiometric dating and planetary geology to address these challenges. Two related projects will capitalize on conceptual and analytical advances in the laboratory analysis of planetary materials led by the applicants, as well as the rapidly growing inventory of Martian meteorites in collections around the world, to generate new datasets and knowledge. Project 1, entitled "Secular evolution of Martian magmatism" focuses on placing robust new age constraints on Martian volcanic processes. Previously, this has been very difficult because the samples have experience extreme compression and heating during impact events, which disturb the isotopic systems used for dating. We will overcome this using advances led by Darling in identifying nanoscale deformation features in dateable crystals that can be avoided or targeted for radiometric dating using the latest techniques in mass spectrometry. Project 2, entitled 'Martian Breccias; the missing link in the search for Meteorite Source Regions on Mars?' focuses on linking the meteoritic and remote sensing records to build a more complete picture of the Martian crust. This will be achieved by resolving the origin and spectral signature of newly discovered brecciated rocks that offer uniquely broad sampling of Martian crustal rocks through clasts of different origin, in combination with new and compiled data on the mineralogy and geochemistry for other Martian meteorite groupings. The results will lead to new holistic models for Martian geological evolution. This new knowledge will help to address one of the four Science Challenges of the STFC Science Roadmap1: How do stars and planetary systems develop and is life unique to our planet?