By his own account, he was "the first Englishman (Anglo-Irish) that in the memory of man settled himself to dwell in the county of Mayo."
In the summer of 1584, he prepared a map of Mayo, leaving out the barony of Costello and parts of Gallen and Clanmorris.
Other maps by Browne included one of Connacht, which was completed by his nephew, John, in 1591, and one of parts of County Monaghan.
Browne and his sub-Sheriff, Donnel O'Daly, were killed in an encounter with Risdeard mac Deamhain and Chorrain and Walter na mBuilleadh Burke at Burrishoole in February 1589 at the start of a major rebellion.
John Browne married Ann, daughter of Thomas Kardyff of Dunsink, County Dublin.