Vietnam veteran is Queen's new envoy in Australia
File photo taken in October 2011 shows Queen Elizabeth II escorted by former military chief Peter Cosgrove at the Australian War Memorial in Canberra - by Ray Strange
Cosgrove, now Sir Peter after Prime Minister Tony Abbott this week revived the honours system, said he would be bipartisan and attend to matters which sat within Australian values.
"Values that respect, and uphold equity, compassion, generosity, tolerance and energetic ambition," he said.
Cosgrove, who replaces Australia's first female governor-general Dame Quentin Bryce, assumed the office at a ceremony at Parliament House in Canberra, the 26th person and 13th Australian in the role.
"I am at once humbled and proud to assume the office as governor-general, humbled to know something of the great men and the one woman to have preceded me," he told the upper house Senate.
"And proud beyond description of Australia, of its men and women, and of their history, their heritage, their present genius and their hopeful future."
The governor-general's role is to maintain direct contact with the Queen, who is Australia's head of state, and the British monarch delegates executive power to them in almost every respect.
They can open and dissolve parliament, commission the prime minister and appoint ministers, rubber-stamp laws passed by parliament and appoint judges and diplomats.
Though the role is largely ceremonial, the governor-general can intervene as occurred in 1975 when then governor-general John Kerr dismissed the government amid a constitutional crisis over deadlocked budget bills.
Abbott, a staunch monarchist, stoked republican dissent with his revival of the honours system this week, but a 1999 referendum to become a republic failed and the Queen is well loved in Australia.
Bryce hinted at support for a republic in one of her final addresses and Cosgrove, an avowed monarchist, has said he would be guided in his new role by "the will of the people".
Cosgrove, a graduate of the Royal Military College, Duntroon, served as a platoon commander in Vietnam and was awarded a Military Cross for his work during an assault on enemy positions there.
He came to prominence in 1999 when he was appointed commander of the international peacekeeping mission in East Timor, overseeing more than 11,000 troops from 22 nations.
He was promoted to army chief in 2000 and two years later became chief of the entire defence force before retiring from active service in 2005.
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