A staggering collection of early golf clubs including one made for a Scottish duke who commanded Europe's only private army is set to sell for in excess of £750,000. 

The Roberto Family Trust Golf Collection is made up of around 130 clubs which go back more than 300 years. 

It has been assembled over the past 50 years by Will Roberto, who has hunted down rarities through a combination of detective work and knocking on people's doors. 

Experts are calling the collection "one of the top five" in the world. 

One of the clubs is known as the Duke of Atholl's Heavy Iron, made in around 1780. 

It was the property of John Murray, 4th Duke of Atholl (1755-1830), whose family seat was Blair Castle in Perthshire, Scotland

The duke, who commanded the only private army in Europe, the Atholl Highlanders, would have used the heavy iron to get himself out of the most difficult lies. It has been valued at £20,000. 

A 1780 long nose wooden headed putter by Leith club maker John Dickson is estimated to sell for £12,000. 

The most valuable club is a left-handed, child's or light spur toe iron, from around 1690-1700. One of only eight such clubs to exist, it has an estimate of around £75,000. 

Another valuable item is a bowmaker's long nose play club from between 1750 and 1780 which is expected to sell for £40,000. 

And a square toe iron circa 1770-1780 by an unknown maker, from the famous 'Woking Collection' of Woking Golf Club, Surrey, is valued at £25,000. 

On top of the antique golf clubs, there is also a bronze statue of amateur champion John Laidlay from 1895 which is estimated to sell for £40,000. 

Laidlay was a Scottish amateur golfer who invented the most popular golf grip used today. 

He won more than 130 amateur medals during his playing career and representing Scotland every year from 1902 to 1911. He has been called the 'last of the gentlemen golfers'. 

Despite the clubs being from Scotland and England, the collection has been assembled over many decades in the USA. 

Bonhams will be selling the clubs and memorabilia in individual lots on March 29 in Los Angeles, USA, with total sales expected to hit around $1 million (£800,000). 

Kevin McGimpsey, Bonhams golf specialist, said: "The Roberto Family Trust's outstanding collection of early golf clubs and other golf memorabilia ranks among the top five in the world. 

"It represents a lifetime of enthusiasm and connoisseurship and provides an unrivalled opportunity to acquire pieces of great historical significance and rarity." 

Will Roberto added: "Putting together this collection has been a wonderful, absorbing hobby which has given me decades of pleasure. 

"The time has now come for a new generation of collectors to enjoy these fascinating objects."