I wonder how many times I have visited this church's more famous neighbour at Thornham Parva since last coming here? And yet, I have always thought of it fondly. I remember my first visit here in the 1990s, being surprised and pleased to see a sign down at the roadside telling me that the church was open. At the time, I had visited several hundred Suffolk churches, and although I had found most of them open, this was the first time I'd come across a church openly advertising the fact. Nowadays, such signs are commonplace, but coming back here in September 2018 I was happy to note that Thornham Magna still has its sign out by the road.

St Mary Magdalene's open welcome, and its high quality 19th Century restoration, are perhaps both symptoms of the philanthropy and generosity of the Henniker family, of nearby Thornham Hall. This is the Henniker church. If you walk westwards of the tower, you will see Thornham Hall over the fence, across a field. You will also find yourself standing among the Henniker graves, which are as understated and restrained as the Hall itself.

Anyone who knows this part of Suffolk will surely love it, a landscape of wooded lanes and gently rolling fields. And the church gets a good number of visitors, for the popular Thornham Walks wind in the woods beyond the church, and there is a good pub down in the village.

The church is attractively set above the lane on a cushion of green and brown, although the 14th century tower is rather forbidding, not least because of the flat effect of the east wall caused by the buttresses being flush with it. There is something similar at Rendlesham. The late medieval porch is elaborate, with three niches which would have contained a rood group before the Anglican reformers removed them only a few decades later in the middle of the 16th Century. Incidentally, the odd way in which the porch abuts the window to the east of it might suggest that a rebuilding was planned, but the Reformation intervened.

You enter what is inevitably a rather dark church, narrow and aisleless, the few windows filled with a range of coloured glass. The gloved hand of lukewarm ritualism fell heavily here in the 19th century thanks to the Henniker family wealth, and consequently not much that is medieval survived. This church has none of the rustic medieval charm of its neighbour at Thornham Parva.

But in any case you come here for the Victorian era, to see how a landed country family in that period of renewed confidence and triumphalism took its parish church to task and remembered itself in death, for the Hennikers have their memorials here, and what a contrast they are to the triumphalism of the Tollemaches at Helmingham or the Poleys at Boxted. here, there is a feeling of understatement. The most memorable and striking on a first visit is probably that to Edward Henniker, who died in 1902. This is the window in the south-west corner of the nave, with figures by Edward Burne-Jones reused by Morris & Co a few years after the artist's death. A gorgeous St Mary Magdalene, a mournful St John and the rather sombre Blessed Virgin stand as they would have done at the foot of the cross.

The big restoration had happened here in the 1850s, rather early for Suffolk and consequently the patron and his workmen had a fairly free hand. The elegant, well-proportioned screen, in a typically bubbly late medieval East Anglian style, was made by the Ipswich carver Henry Ringham for a church in Surrey. It was exhibited in the Great Exhibition of 1851, but never seems to have been installed in Surrey. The Hennikers bought it in 1856 and had it installed here, where it looks very well.

The glass on the north side of the nave by William Miller was installed through the 1850s in memory of members of the Henniker family. Inscriptions were carved into the sill below each window, but a rather unfortunate error in the date of one (the inscription below the central light of the middle window has the infant John Chandos Henniker Major being born in 1844 and dying in 1842) meant that the inscriptions were soon covered by painted plate metal replacements. Today, these lie on the sill below the original inscriptions, so you can see both. The unfortunate child, who had actually been born in 1841, is shown in the light above being held in the arms of Christ. In the left hand light, his father Major Henniker kneels in 14th Century uniform holding a spear. He died at Pau in the Pyrenees a few months after the death of his son.

The mawkish scene on the other side of the nave, depicting the three women at the tomb of Christ, is typical work of the 1880s by WG Taylor, but the other glass up in the chancel is also by William Miller, also of the 1850s. Up here in the sanctuary is the Hennikers' one attempt at full-blown triumphalism, the memorial to John Henniker Major. It is by Joseph Kendrick. Faith clasps the urn looking downcast, a swan or cormorant peeping from behind her, while Hope looks up, resting against her anchor, a characterful face at once sorrowful and earnest.

The Henniker memorials are an interesting history of the colonial adventures of an established landed family. One was killed in Spain, in the Battle of Almanza, while another served in the Egyptian Campaign... and throughout the South African War. The memorial to the Major Henniker commemorated in the window is by William Woodington, who, Sam Mortlock reminds us, was also responsible for the bronze reliefs around the base of Nelson's Column. There are seven Henniker hatchments, an unusually large number even for Suffolk, which has more than any other county apart from Kent.

But my favourite memorial of all, I think, is the simple one to Martha Catherine Henniker, who was born in July 1838 and died just three months later. The tender plant shed forth its beauteous form, look'd round upon this boisterous world, found its chilling blasts too rough, droop'd its head and died. Isn't that lovely? I wonder if it can have been a comfort. It is signed CRH, perhaps her mother or father. Leaving, you can't help thinking that perhaps the grieving figures in the Burne-Jones window reflect something of this sadness in Martha Catherine Henniker's inscription.