Allen led the first professional excavation of a European site in Australia, the 1840s military settlement of Victoria, which was established at Port Essington at the northernmost point of the Northern Territory.
He also worked on the Lapita culture, tracing the expansion of Polynesian settlement through its distinctive pottery style.
[1] In the 1990s, he played a prominent role in the debate over the forced repatriation of Aboriginal remains.
In 2012 he was elected a foreign associate of the United States National Academy of Sciences.
[3] In 2018, by then a Professor Emeritus, Allen co-authored a paper showing evidence of earlier-that- expected arrival of humans in Australia.