Michael Ball and Alfie Boe will sing at the castle this summer

The new tour follows the success of their platinum-selling album Together and 29 sold-out shows across the UK in 2016.

Having first met 10 years ago, performing together in Kismet at the London Coliseum, Michael and Alfie became lifelong friends.

That same year, Michael made history as the first musical theatre star to be given a solo concert at the Royal Albert Hall’s BBC Proms, and he asked Alfie to join him to perform at the classical music festival.

The pair say: “We have always wanted to work together, it was just a case of getting the timing right.

“We are so grateful to all our fans who have supported us and everyone involved for believing in us.

“We are literally having the best time and are so happy with the success of the album and the tour.”

The two critically-­acclaimed artists have received a plethora of prestigious awards, record-breaking sales and chart successes.

Over his extraordinary 30 year career, Michael’s outstanding performances have made smash-­hit box office history.

He is a double Olivier Award winner, multi-­platinum recording artist, top selling live concert performer and a hugely popular radio and TV presenter.

Alfie’s exceptional voice has made him Britain’s most popular and biggest-­selling tenor.

He has conquered the world’s greatest opera stages and arenas, led the cast of Les Misérables and performed at the Queen’s Diamond Jubilee Concert at Buckingham Palace– as well achieving UK album sales of more than a million, and four top 10 albums.

Their Lincoln Castle show is on June 25.

Ticket details are available on www.lincolncastle.com