This lecture by the instructor from Oxford University explores the influence of magnetic order on topological metals and semiconductors. It covers topics such as the impact of magnetic order on band topology, topological protection, and the creation of Dirac and Weyl semimetals. The lecture delves into the concept of topology, protected band crossings, and anomalous Hall effects induced by magnetic fields. Examples from compounds like YbMnX₂ and EuCd₂AS₂ are discussed, emphasizing the importance of magnetic structure details in understanding electronic topology.