A darker part of Pembrokeshire’s history will feature in an SFC programme this weekend.

Sir Thomas Picton is remembered as one of Wales' most famous soldiers and the only Welshman to be buried in St Paul's Cathedral, London.

A grand painting of him sits in Carmarthen Crown Court and a statue in the town, there's a memorial to honour him in Cardiff City Hall and streets across the world have been named after the man from Pembrokeshire.

Despite being remembered as a war hero, Picton's story is part of a very dark period in British history.

This sinister past is the subject of the first of a new series of Dylan ar Daith, which profiles prominent Welsh figures from the past who made their mark often in faraway lands.

In the programme on Sunday, 17 September, Picton's story is followed from Gibraltar where he was a young soldier, to Waterloo where he became a famous officer. But between these two periods, Thomas Picton's influence was less positive and raises questions about his and the British Empire's role in a history now considered a disgrace; slavery.

Picton was governor of the island of Trinidad for six years, at a time when over half the people living there were slaves.

"Most Welsh people remember Thomas Picton for winning important battles and for dying a hero at Waterloo," says presenter of the series, journalist Dylan Iorwerth. "But Picton could be very strict and incredibly cruel. All types of torture took place under his rule. Slaves suffered burning of the skin, branding and the cutting of ears - Picton's choice of torture."

British authorities were worried that slaves in Trinidad would copy the example of those in countries like Haiti where slaves led the battle for freedom. When there was any suggestion of rebellion, Thomas Picton acted immediately.

"Funds from the slave trade gave a big boost to the steel industry in South Wales and the slate industry in the North, although this is now remembered with shame," says Dylan Iorwerth, who travels to Trinidad, China, Morocco and Israel among other places during the series researching stories about influential Welsh people.

There was one case of violence which had a great effect on the life of Thomas Picton and left a dark cloud over him for ever. A 14-year-old girl in Trinidad was accused of stealing money and Picton decided she should be tortured.

"This case of violence - the torture of Luisa Calderón - had a great impact on the life of Thomas Picton and made him a hated man by many. As governor he faced over 30 charges of torture in Trinidad and he was summoned back to Britain to face the court of law," says Dylan Iorwerth.

Following his death in Waterloo, a memorial for Thomas Picton was erected in St Paul's Cathedral in London and another in Carmarthen, and both are still the subject of controversy today.