Streedagh beach was the setting for young love in the TV drama Normal People, but its latest screen depiction reveals a dark history of plunder and slaughter on the golden sand.

Instead of romance among the dunes, viewers encounter drownings, stabbings and hangings on this bucolic stretch of Ireland’s Atlantic coast. And unlike the adaptation of Sally Rooney’s novel, it’s all true.

The docudrama Armada 1588: Shipwreck and Survival tells the story of Francisco de Cuéllar, a Spanish captain who was part of Spain’s ill-fated attempt to invade Elizabethan England and ended up a fugitive in the west of Ireland.

After surviving naval battles and storms he found himself marooned in a “land of savages” – known in the present day as County Sligo – where he was hunted by English soldiers and repeatedly attacked and robbed by hostile locals, the start of an epic journey home verging on Odyssean.

The film was made by Spanish Armada Ireland, a voluntary group based in Sligo that used €100,000 (£90,100) of community development funding to recruit an international cast and crew and make a swashbuckling half-hour film.

“It’s an incredible story of survival,” said Micheál Ó Domhnaill, a producer. “It had crept into lots of other stories, but it was surprising that no film had ever been done specifically about De Cuéllar.”

The screenplay was based on an account the Spaniard wrote in October 1589 after escaping Ireland and stopping in Amsterdam on his way back to Spain.

A Spanish actor, Fernando Corral, plays the lead, and other Spanish and mainly Irish actors play sailors, soldiers, robbers, good samaritans and chieftains. CGI recreates storms and doomed galleons tossed by waves. Artists’ drawings fill in other sequences.

RTÉ screened the film last month and for €4.99 (or £4.45) it is now available to stream or download, with proceeds going to an armada visitor centre in the village of Grange, a few miles from Streedagh beach.

So far there have been about 2,000 paid downloads. The English version has been viewed in 25 countries and the Spanish version in 29.

Armada 1588 will not rival Normal People for audience size, but it does cast a different light on the strand where Rooney’s characters, Marianne and Connell, get to know one another.

“It’s strange that we should have two productions that are really different from each other on the same beach,” said Ó Domhnaill. “Normal People filmed on really sunny days when it was at its absolute best. We filmed in the worst time of year, which replicated conditions in 1588.”

Spain’s King Felipe II dispatched a fleet of 130 ships to transport an army from Flanders to England to overthrow Queen Elizabeth I, restore Catholicism and shore up his power.

Spanish bungling, English and Dutch resistance and bad weather scattered the armada, sending its ships on a circuitous journey around Scotland and Ireland. Only about 80 made it home.

De Cuéllar captained the San Pedro. For breaking formation in the North Sea he was court-martialled on another ship and sentenced to death. That and two other ships foundered off Sligo, drowning hundreds of people. Those who made it ashore were robbed by locals and butchered by English troops.

De Cuéllar, stripped and battered, escaped inland where he spent seven months being alternately brutalised and aided by locals. Two chieftains who sheltered him, Brian O’Rourke and Tadhg Óg McClancy, were later executed.

In his chronicle, De Cuéllar said O’Rourke’s wife was “very beautiful in the extreme, and she showed me much kindness,” a line that has prompted centuries of speculation.

After myriad adventures, including a siege, an offer of marriage and another shipwreck, the fugitive made it back to Spain where he was pardoned and went on to serve the Spanish crown in Naples and the Americas. “He must have been the most resourceful character,” said Ó Domhnaill.

Eddie O’Gorman, the chair of Spanish Armada Ireland, hopes the film will entice visitors to Streedagh beach, which overlooks sunken wrecks. “It’s an extraordinary treasure. And the fact we have this great hero, there’s nothing to match it.”