A groundbreaking modern holiday home inserted into the walls of an ancient castle has won this year's Riba Stirling Prize for architecture.

Astley Castle was chosen from six shortlisted buildings to win the annual award, which is the Royal Institute of British Architects' highest accolade.

Riba president Stephen Hodder called it "a real labour of love".

"Astley Castle is an exceptional example of how modern architecture can revive an ancient monument," he added.

Image copyright Various Awarded by Royal Institute of British Architects

Architects must be Riba members to be in the running, and the building anywhere in the EU

In partnership with Riba, BBC News is running an online vote and a series of features on the shortlisted buildings Special report on the buildings Riba Stirling Prize

Designed by Witherford Watson Mann Architects, the fortified manor house in Warwickshire also topped the BBC website's readers vote on Wednesday.

The castle took a 27% share of the 65,000 that took part in the vote.

It beat off competition from an eclectic Stirling Prize shortlist that included the Giant's Causeway Visitor Centre in Northern Ireland and Park Hill, a renovated 1960s estate in Sheffield.

Other contenders included Newhall Be - a suburban development in Harlow, Essex; the University of Limerick Medical Centre and Bishop Edward King Chapel in Oxfordshire.

Once home to the aristocratic Grey family, Astley Castle has links to three queens of England and gained Grade II listed status in 1951.

Mr Hodder said he was "delighted" to present the winning architects with the Stirling Prize trophy at a special ceremony at Central Saint Martins in London's King's Cross.

Gutted by fire

Analysis It is not without irony that Astley Castle in Warwickshire, which is nearly 1,000 years-old, has won the 2013 Riba Stirling Prize - an award for contemporary architecture. The reason it has done so is because of the way in which the architects, Witherford Watson Mann, have sensitively brought the building up to date and back to life. The judges' decision is in-keeping with a trend for romantic nostalgia that exists across the arts, that sees writers such as Hilary Mantel 're-authoring' history, and hip designers like Wayne Hemingway exploring all things 'vintage'. Astley Castle was once a mediaeval manor, before becoming a Parliamentarian garrison during the English Civil War, and has now been transformed into a 21st Century holiday home. But if you want to stay there you'll have to be patient - it's already booked up until 2015.

Before the firm started work on the 12th Century property, Astley Castle had been lying in ruins and was in a state of collapse, gutted by a 1978 fire.

It was renovated on behalf on the charity, the Landmark Trust which rescues important buildings that would otherwise be lost.

"Rather than a conventional restoration project, the architects have designed an incredibly powerful contemporary house which is expertly and intricately intertwined with 800 years of history," said Mr Hodder.

He continued: "Every detail has been carefully considered, from a specific brick pattern to the exact angle of a view, resulting in a sensually rich experience for all who visit. It was realised in true collaboration between a visionary client, designer and contractors."

Now in its 18th year, the Stirling Prize is awarded to the best new building of the year, constructed in the European Union and designed in the UK.

2012's winner was the Sainsbury Laboratory, an £82m plant research centre at the University of Cambridge, which beat London's Olympic Stadium and Belfast's Lyric Theatre.

Video by: John Galliver