Dating a church tower can feel like a puzzle, but its windows are often the most honest witnesses. Styles changed with fashion, and masons rarely bothered to update older openings unless they had good reason. By reading the shape, tracery and position of a tower’s windows, you can build a rough chronology of its development. This method will not give you an exact year, but it will tell you whether you are looking at Norman work, a 14th-century remodelling, or a Victorian restoration.

Why the Lowest Window Matters Most

The lowest window in a tower is often the earliest surviving feature. Towers were usually built from the ground up, and the base is the least likely part to be rebuilt. In a Norman tower, you will typically find small, round-headed windows with deep splayed reveals. Some are barely wider than a slit. The arches are semicircular, the stonework is thick, and there is no tracery at all. If the belfry openings above also have round heads, you are probably looking at an 11th- or 12th-century tower.

• Norman: round arch, small opening, deep splay, no tracery.
• Look for: reused Roman brick or stone, massive walls, simple imposts.
• Beware: a round-headed window can be a later insertion, so check the surrounding stonework.

Lancet Windows and the Early English Style

By the early 13th century, the pointed arch had arrived. The lancet window is the signature of the Early English style: tall, narrow, and pointed, often grouped in twos, threes, or fives. There is still no tracery – just a single opening with a pointed head. In a tower, you may see a single lancet on the lower stages, then paired lancets at the belfry level. The stonework is lighter, the walls thinner, and the openings taller than Norman work. If you spot a group of narrow, unadorned pointed windows, you can confidently place the work in the 13th century.

Geometric Tracery: The Decorated Signature

The 14th century brought tracery – stone bars dividing the window into patterns. In the Decorated period, these patterns are geometric: circles, trefoils, quatrefoils, and cusped shapes. Later in the period, the tracery becomes flowing, with ogee arches and curving lines that look almost organic. Tower windows from this time are wider and let in more light. Belfry openings often have two or three lights with a circle above. If you see a window where the tracery forms a clear geometric shape, you are likely in the 1300s. The stonework is more refined, and the mouldings are deeper.

Perpendicular Windows: Vertical Lines Tell a Later Story

From the late 14th century into the early 16th, the Perpendicular style dominated. Here, the tracery is dominated by vertical mullions that run straight up to the arch, crossed by horizontal transoms. The result is a grid of panels. Arches are often four-centred – a flatter, wider pointed shape. Tower windows become large, sometimes filling most of the wall between buttresses. Belfry openings have straight vertical lines and panel tracery. If you see a window that looks like a series of tall rectangles with a flat-ish arch, you are looking at Perpendicular work. This is the last great medieval style before the Reformation.

What to Ignore: Later Insertions and Restorations

Not every window belongs to the tower’s original build. The 17th and 18th centuries saw modest repairs, but the 19th century brought aggressive restoration. Victorian architects often replaced medieval windows with new ones in a Gothic style, or inserted Perpendicular windows into Norman towers. A single grand window in an otherwise early tower is suspicious. Look at the stone: original medieval work is often weathered and irregular, while Victorian stone is crisp and uniform. Check the jointing and tooling marks. Also remember that towers were sometimes heightened, so the upper windows may be later than the base. Date the window, not the whole tower.

A Simple Field Method for Rough Dating

Start at the bottom and work upwards. Photograph or sketch each window in turn. Note the arch shape, the presence or absence of tracery, and the number of lights. Use binoculars to see details high up. Then compare your notes against the sequence above. A tower with a Norman base, Early English belfry, and Perpendicular top tells a story of centuries of change. Always be cautious: a single window can be moved or replaced. But as a rough guide, window shapes are reliable, practical, and deeply revealing. With a little practice, you will read a tower’s history in its openings.