There are only four surviving copies of Magna Carta, the 13th century document with which King John of England introduced laws that have influenced the writers of many of the world’s constitutions.

One of the copies goes on show in Lincoln Castle this summer in the culmination of a major plan to upgrade a building that has a history dating back to Norman times.

Two copies of the famous document are housed in the British Library and the two others in Lincoln and Salisbury Cathedral.

This month, all four were brought together for the first time in London as England prepares to celebrate 800 years since the document was sealed.

Magna Carta on display in London.

Lincoln’s square copy has been on display in the US during the £20 million (€27m) renovation of Lincoln Castle, which has in­cluded work on the Victorian and Georgian prisons and creating an underground vault to house both Magna Carta and the Charter of the Forest.

The latter is regarded by some as more important because it dealt with the rights of common people, while the more famous document enshrined into law the rights of the barons.

The British and US constitutions both owe their origins to Magna Carta, or Great Charter, which ensured that all free men had a right to justice.

In another link to the past, the building where Lincoln Crown Court sits is situated within the walls of the castle.

I visited Lincoln Castle and was able to see most of the grounds despite the extensive refurbishment works and it was easy to see the grand plans coming to life.

When completed, the refurbishment will allow visitors to walk the entire route around the castle walls, and the installation of a lift will ensure wheelchair access to the ramparts.

Looking at the stunning views of the hilltop city and surrounding countryside stretching away for miles, it is easy to imagine yourself as one of the castle guards, keeping watch as an army assaults the walls, firing arrows through the narrow slits and even throwing rocks on to the heads of marauding troops.

The castle grounds.

Inside Lincoln Castle.

Throughout the summer, Lincoln Castle is the stage for med­ieval jousting tournaments and also the starting point for the graduation ceremony for students from Lincoln University.

In the winter the grounds host a popular German Christmas market, which brings in tourists by the busload.

A short walk from the castle is the stunning cathedral, the original home of the copy of Magna Carta, which will be revealed in its new setting on April 1.

Standing in the full glory of the cathedral, built shortly after the castle on the site of the old Roman city, it is easy to become lost in the majesty of this spectacular temple of religious worship.

A short downhill stroll along the narrow streets towards the centre of Lincoln brings my visit to an end. Well, almost.

The perfect day was rounded off by afternoon tea in one of many quaint tea rooms and restaurants that dot the winding thoroughfares and alleys.

There is no institution more English than a cup of tea and a slice of cake, and what better place to enjoy it than in one of the country’s most historical cities?