He was the eldest child of Edward and Jane Chapman and came from a long line of sportsmen who were both accomplished hunters and acclaimed naturalists.
His grandfather, Joseph Crawhall, was an accurate grouse shot in Hexhamshire, as well as being a founder member of the National History Society of Northumbria.
But it was a friend he made at Rugby School, F C Selous, who inspired his lifelong love of travel and adventure – a world away from the moors of Northumberland.
Chapman joined his father's firm, the Sunderland-based Lambton Brewery, after leaving Rugby, travelling to Portugal, Spain and Morocco as part of his work in the wine trade.
The pair became joint managers of a 40-mile (64 km) stretch of coast at Coto Donana, near the river Guadalquivir, in 1882, which they ran as a nature reserve.
It was here Chapman discovered Europe's major breeding ground for flamingos, and helped save the Spanish Ibex – a wild goat – from extinction.
His smart country home was surrounded by small plantations, moorland and gardens, all designed to attract birds, animals and other naturalists in profusion.