The theme of the 2021 Chief of Army History is Contingencies and compromises: mobilising the Australian Army. Since its beginnings the Australian Army has had to mobilise to meet challenges across the globe. The 2021 Chief of Army History Conference will focus on the history of mobilising Armies to meet different challenges. Presenters will to explore the challenges of mobilising land forces throughout history to meet different security threats and the successes, failures and lessons these present for the Army today. The conference brings together panellists from a broad range of backgrounds - military personnel, strategic advisers, and military historians - to share their expertise on the challenges of mobilising land forces against different security threats. They will bring out the lessons from past successes and failures that can inform the Australian Army today. The papers presented at each conference have reinforced that some problems are perennial, and that it is better to arm oneself against repeating these mistakes by learning the lessons from the past. Army views this conference as an opportunity to use history to better educate and prepare its people for the challenges they may face in the future, as well as to provide guiding principles from which to approach planning for future operational, administrative or modernisation requirements. Enquiries: AAHU.Conference@defence.gov.au