A portrait of the City of London

My former impression of guided tours as flocks of badly-dressed tourists being herded round a city's top sights by a frantic umbrella-waver was revised somewhat following a centenary tour of Madrid's Gran Via. With just twelve participants and focused on a specific theme, this tour was more manageable and informative - and, surprisngly, fun. Keen to get a better insight into London after moving, it was with interest I read about Context Travel's 'walking tours for the intellectually curious'. Intellectually curious? Well, I definitely like more from a guided visit than a vague overview and a little bit of pointing at significant statues, so I suppose that puts me in the right category.

Operating in twelve cities worldwide, Context's walking tours are available privately or for groups of no more than 6. Eager to redress my ignorance of my new city's history, I opted for the group version of their historical Portrait of a City walk, and was impressed to find that I only had to share the knowledgeable and engaging Caroline with 3 others. All Context guides are experts in their subject area, with the aim of making each tour more akin to an ambulatory al-fresco seminar. With a PhD in archaeology, a university lectureship and a keen interest in architecture, Caroline was certainly well-qualified to lead the four of us through the City of London's history. It's an area many people (myself included) merely pass through only to get to work, no doubt unaware of much of its long history and the stories behind the monuments rubbing shoulders with office blocks and bars. Fortunately for us, the City's commercial leaning means it's deserted at the weekend: ideal for getting to grips with 2000 years of history on a Sunday morning.

Tower of London

Beginning at the Tower of London (the south-east corner of the Roman city, as I now know), Caroline gave us an overview of the three hours ahead of us and the development of the borough known as the City of London from Roman times to Boris Johnson's times. Fighting our way through the stream of cyclists out in force for Boris's Sky Ride, we made our way to the longest-functioning church in the City, All Hallows by the Tower, where Anglo-Saxon archways remain among the post-Blitz reconstruction. The real treasure is in the crypt however: no, no crusty kings decaying in the shadows post-Tower execution, but a well-preserved section of floor from a second-century Roman home, unearthed during twentieth century rebuilding. Also hiding in the downstairs gloom is a mini-museum, featuring a model of the Roman city. Talking us through its boundaries, Caroline explained that London's north-south divide was more than just a physical one even in Roman times: Southwark was outside the city walls, seen as a potentially seditious area full of untoward goings-on. Along with plenty of playhouses, this naughty neighbourhood also featured a market approximately where Borough Market stands today.

Moving on towards the financial heart of the borough, we detoured into a hotel's courtyard to peruse the remains of the old city walls. With a very straight Roman base and more haphazard medieval top section, this almost hidden stretch of wall is now home to a number of contented-looking pigeons roosting in old look-out points. As we passed down amusingly-named streets such as Crutched Friars (and later Poultry, my personal favourite), our guide explained that the modern street names relate to the former trades which went on there, with Vine Street the site of former vineyards and Crutched Friars once home to the Church of the Holy Cross.

The Gherkin

From Roman ruins we were whisked forward to modern times with a close-up view of that recent entry onto London's skyline, the now-iconic Gherkin (or the less catchy 30 St Mary Axe, as it's officially known). Designed by Norman Foster and completed in 2003, the eco-friendly building is an example of computational architecture (for the non-architecturally savvy like myself, this means that its shape is such that architects couldn't physically draw it, but planned it using special software). There was great opposition to its construction, and you can understand why given the way it towers above its architecturally rather different neighbours, but I was won over by its smooth shape. Less aesthetically pleasing was the Richard Rogers-designed Lloyd's building around the corner, one of the architect's typical 'bowels of the building on the exterior' creations, topped with blue-painted cranes to give an image of permanent construction. Whether it's to your personal taste or not, the 1986 edifice was undeniably a bold statement for the British institution that is Lloyd's.

Lloyd's Building

Bank of England

Caroline whisked us back into the past for an exploration of the Victorian Leadenhall market (unfortunately undergoing refurbishment works) and on to Monument, Christopher Wren's austere memorial to the Great Fire of London in 1666. The fire wreaked havoc in the City, destroying four-fifths of it. Wren was tasked with much of the reconstruction work after the fire's devastation, rebuilding a total of 51 churches including St Paul's Cathedral. From the official we moved back to the seditious: Caroline explained that the City was traditionally an area touched little by kingly influence, but the explosion of coffee houses in the late seventeenth century as an alternative to pubs riled those royals as they felt threatened by activities that took place there. No, not the serving of skinny lattes as opposed to mugs of ale, but discussion of deals among rich tradesmen and early-modern political debate. As a result, the moanrchy made their presence felt in the City through the construction of the Bank of England - no doubt to great effect, as the imposing facade of the huge building can't exactly be ignored. Nor can the nearby Mansion House, the vast Georgian townhouse which serves as the Mayor's residence and office space.

Guildhall

After a final stroll past Guildhall, the palatial seat of the government of the City of London corporation, under whose courtyard lies a recently-revealed Roman amphitheatre, it was time to make our way through Cheapside to Wren's triumph, St Paul's Cathedral, the final stop on the tour. Thanks to Caroline's informative but accessible style, the walk had passed quickly, but left us all feeling that we'd learned far more than on an average guided tour. After uncovering the City's history and getting up close to its many monuments, it's now much more than just a business district to me.

St Paul's Cathedral

• You can find out more about Context's 17 different London walks, which range from history to family-orientated tours, here.