Australia’s new defence chiefs: How Mark Hammond, Susan Coyle and Matthew Buckley climbed to the top

Australia’s top military leadership will be reshaped in July, with three long-serving officers — including the first woman elevated to be Chief of Army — stepping into the most powerful roles in the Defence Force.

Between them, Vice-Admiral Mark Hammond, Lt-Gen. Susan Coyle and Rear-Admiral Matthew Buckley bring more than a century of combined service — from submarines and operational theatres to cyber warfare and strategic command — but also quieter personal lives that offer a glimpse of the people behind the uniforms.

Vice-Admiral Hammond’s elevation to Chief of the Defence Force caps a career that began at the lowest rung of the Navy.

He joined in 1986 as an electronics technician before commissioning as an officer two years later — a trajectory rarely seen at the highest levels of command.

After early service in frigates, he volunteered for submarines, where he would spend much of his career, qualifying across multiple classes and commanding HMAS Farncomb on operations throughout the Indo-Pacific.

Admiral Hammond’s experience extends well beyond Australia, with postings in Washington DC and close work with allied militaries, including the United States.

He later served as chief of staff to the chief of the Defence Force and as Australia’s liaison to the US Joint Chiefs of Staff, earning the US Legion of Merit.

Since becoming Chief of Navy in 2022, Admiral Hammond has overseen the service through a period of significant transition, including the early phases of the AUKUS nuclear-powered submarine program.

His career has been underpinned by extensive academic study, including degrees in science, management and maritime studies, and executive training at Harvard Business School.

Away from the uniform, Admiral Hammond’s interests are more nostalgic: he has a passion for antique wooden boats and World War II submarine history, and follows a wide range of Australian sport, from cricket to rugby league as a South Sydney Rabbitohs supporter and AFL, where he backs Port Adelaide.

He shares two children, Josh and Jessica, with wife Jodi.

This comes as Lt-Gen. Coyle makes history as Australia’s first female Chief of Army, becoming the 42nd person to hold the role after nearly four decades in uniform.

Lt-Gen. Coyle enlisted in the Army Reserve in 1987 before graduating from the Royal Military College into the Royal Australian Corps of Signals, building a career that has spanned tactical command, operational deployments and senior strategic roles.

Her service has included deployments to Timor-Leste, the Solomon Islands, Afghanistan and across the Middle East.

In 2020, she became the first woman to command Australia’s joint task force overseeing operations in the Middle East, a milestone in a career marked by a series of firsts.

The mother-of-three has commanded at every rank, including leading Forces Command and the 6th Brigade, and now heads the Joint Capabilities Group, where she is responsible for space, cyber and national support capabilities.

Lt-Gen. Coyle’s academic background includes postgraduate study at the US Army War College and Australian universities, as well as executive training at Harvard.

She is married to Mark, an Army engineer, and they have three children — Jessica, Susie and Jack — whom she has described as “mostly charming young adults”.

Outside work, she enjoys musical theatre, reading and travel, and has consistently emphasised a “people first” approach to leadership, with a strong focus on supporting veterans and their families.

Meanwhile, Admiral Buckley will step into the role of Chief of Navy, continuing the service’s strong submarine lineage at a time of profound change.

Born in Sydney and raised on the NSW South Coast, the father-of-three joined the Navy in 1990 and quickly specialised in submarines, serving in both Oberon and Collins-class boats.

His early career included a two-year exchange with the Canadian Navy in Halifax, broadening his experience of allied operations, and he later commanded HMAS Collins.

Admiral Buckley went on to lead the Australian Submarine Force and has held a series of senior roles across capability, operations and personnel, including Director General Navy Operations and Head of Nuclear Submarine Capability.

He is currently Deputy Chief of Navy and has been closely involved in preparations for Australia’s transition to nuclear-powered submarines under AUKUS, as well as the introduction of new surface and autonomous systems.

A graduate of the Australian Defence and Strategic Studies Course, where he received the Secretary of Defence–Chief of Defence Force prize, Admiral Buckley also holds degrees in arts, strategy and policy, and international relations.

His career has been shaped by extensive service across the Western Pacific, fostering a deep strategic interest in the Indo-Pacific region.

With more than 35 years in uniform, he will take command of the Navy as it undertakes one of the most significant capability transformations in its history.

Admiral Buckley is supported by his wife Ingrid and their three sons, Xavier, Joel and Marcus.