Walter Sloane, born 1843, arrived in Auckland from Scotland about 1863, married Margaret Robertson on 2nd April 1868 in St Andrew's Church, Auckland. The Robertson family operated the first sawmill in Auckland (Vulcan Lane) where they made the Waitangi Flagpole for celebrations. Walter and Margaret's son, Andrew Dunbar Sloane, moved to Wellington due to Asthma problems about 1900. Starting his career as chemist he became an army captain in WWI. On his return from the war he established the auctioneering business Dunbar Sloane Ltd on Lambton Quay.

The business has been through good times and recessions, however survived with a Sloane at the head of operations. As we head into the 21st century, the Wellington head office is in the capable, expert hands of valuers Bettina Frith and Anthony Gallagher.

Dunbar Sloane Snr and Dunbar Sloane Jnr manage Dunbar Sloane Auckland, established in 2000.