Easter Sunday

by James D. Wenn

 

A bridge of mathematics

One of the surest signs of Christian continuity in these islands in the Late Antique period is how in 664, at the Synod of Whitby, there was a question to be answered. This question regarded Computus, the mathematical calculation of the date of the Christian festival of Easter. The British Isles contained a tradition of an 84 year lunar cycle that had not updated with Rome to a 19 year cycle preferred in Alexandria.

The oldest work of history concerning the English, Bede’s historia ecclesiastica gentis Anglorum, focused heavily on the synod and is globally famous, but some of Bede’s other catalogued works treated mathematics more directly. De natura rerum, et de temporibus libros singulos and Item de temporibus librum I maiorem (traditionally, De natura rerum; De temporibus; De temporum ratione) were motivated by the need to teach Computus.

Ancient Christianity in Britain

If mathematics constituted the proof of a bridge through time, it is our contention at Byrga Geniht that a mathematical (or geometric) bent of mind characterised Christianity in Britain from the earliest time. One of the oldest iconographic depictions of Jesus Christ was found in Hinton St Mary in Dorset in 1963, in the form of a mosaic pavement dated to the fourth century.

Along with the pomegranates associated with resurrection throughout Classical Mediterranean religion, Christ’s portrait is identified through a Chi Rho monogram located behind his head.

This mosaic was manufactured within living memory of Constantine’s vision of a cross or Iota Chi (a simpler monogram, like an asterisk) made of light in the sky, which facilitated his military victory — a campaign to seize control of the Roman Empire started in Britain at York — and paved the way for the legalisation of Christianity in the Edict of Milan in 313.

An echo in contemporary art and thought

Our sculptures — made as processional crosses, and named In Hoc Signo in reference to Constantine’s vision as recorded by Eusebius — show the regular projections of the rhombic dodecahedron.

These projections make forms that show the cross and Iota Chi depending on how you view each one. James Syrett and I worked with Jacob Chandler to produce these using hot-cast bronze and pure gold. They have been exhibited at Shrewsbury Museum and Art Gallery as part of 2025’s Shrewsbury Arts Trail, alongside contemporary solo works by Jacob Chandler, Halima Cassell MBE, and Andrew Logan MBE.

The curation also encompassed modern masters, and Pablo Picasso, Andy Warhol, Marc Chagall and Roy Lichtenstein. In Hoc Signo then featured in our research and art exhibition Number in Time and Space, at the Minories, Colchester’s oldest art gallery. More lately, in March 2026, In Hoc Signo has been exhibited in the Chapel at Magdalene College, Cambridge, to accompany a lecture given by James Syrett for postgraduates and Fellows at his alma mater.

However, the very first showing of In Hoc Signo was at Soulton Hall, which is commemorated by the original aluminium prints of the concept renders of the sculptures, and the work’s logo, hanging in Old Sir Rowland’s Studiolo.

The reason for their location next to a window is the perfect link to a discussion of how Soulton’s design connects to the deep history of Christianity in Britain, especially at the time of Easter.

Soulton’s Easter geometry

The square precinct at Soulton, ten rods by ten rods in imperial units, is oriented roughly facing the cardinal directions, North, East, South and West. The ‘roughly’ contains the value, however, as the square neither matches celestial north, nor the road to Wem as an approximation of a cartographic local line of convenience. Instead, lines from the Aedicule window to the width of the old gate to the Tudor avenue (lately excavated and dated by DigVentures to the sixteenth-century phase) sweep out an arc that includes all of the horizon in which the sun may rise on Easter Sunday. The variation in solar day (calculated by Computus) is accommodated by the old gate arrangement (which may hopefully be reinstated after consultation with heritage authorities).

The basement window to the Aedicule, which poetically resembles the burial chamber of Christ in Jerusalem, is the only central opening in the entire Hall. As the sun rises at Easter, the empty tomb is evoked, and the Mystery of Jesus’ resurrection is conjured in abstract art.

This artistic trope was explored by Albrecht Dürer in his illustrations for the Little Passion, in which a sunrise floods through an orchard gate in the Resurrection. 

This light effect is extremely ancient.

Most western churches are oriented East, with the intention of the daily sunrise contributing such an atmosphere of Christian hope (hope in the Resurrection). Interestingly, church orientations can vary quite dramatically from due East, as sometimes immediate site restrictions play a role, and sometimes local horizons (or, in built-up sites, lack of them) have meant that pointing to a sunrise has interesting effects on orientation relative to the cardinal directions. After this, there is some evidence that some churches have been aligned with the sunrise of specific meaningful dates other than Easter, such as founding days, or the days of saints to whom they were dedicated. Old Sir Rowland’s Soulton was built on an open site, and, unencumbered by physical restrictions, chose Easter.

In Hoc Signo, II: Trinity helps explain the red brick, three-bay, three-storey core block of Soulton Hall, as the 3x3x3 cube within which a rhombic dodecahedron may be mapped, and the 3×3 grid of the precinct.

The sun’s rays at sunrise at Easter, shining along the lost avenue, correspond with the projections of the sculpture. All the masonry mullions and transoms of the windows at Soulton correspond to this In Hoc Signo geometry, as the splayed shafts evoke the poised square-section beams of the three projections, and all are aligned with the dimensional 3D grid of the Easter orientation as they form part of the outer walls of the cube-like Hall.

Where the original mullions and transoms have not been replaced, such as in the Studiolo, there are blocks at the intersections of the mullions and transoms, implying that a shaft of stone could spring forth out of them, just like in In Hoc Signo.

Moreover, The narrow flat fronts of the mullions and transoms run into these in a way that implies the flat faces of the blocks can be divided up as 3×3 grids. The Hall’s commitment to this lattice of theoretical beams is intensified by the two ‘portraits’ of rhombic dodecahedrons (the square quartered poised square), one on the north facade, and one on the south facade, corresponding to the two main doors to the building.

Linking to London via the blood of Christ

Another aspect of the iconography of the Resurrection is the Flag of the Resurrection.

This white flag with a red cross originated in medieval iconography of Easter Sunday, in which Chist ascends from the tomb (or from harrying Hell) holding a lance in triumph, to which is appended a military banner signifying victory over death.

The flag came to be associated with St George (as a military saint defeating evil in the form of a dragon), and then with England (in the time of Henry III), and likely thence to forming the design of the arms of the City of London.

It is Byrga Geniht’s work that has identified that a key aspect of this iconography is the Trinity. The two beams of the cross represent the Holy Spirit (vertical) and the Father (horizontal), so that the gaze of Jesus holding this flag forms a third beam (outwards) creating the In Hoc Signo effect. Garnets crystals naturally form as rhombic dodecahedra, and garnet was consistently used as an allegory for the blood of Christ (the Eucharist) in the high middle ages. The burning ember (carbuncle = garnet) is used in the Book of Ezekiel to reference the form of a conformed soul. The claim upon the rhombic dodecahedron to symbolic power regarding divinity we think owes to its ability to fill 3D volume without gaps — reflecting a harmonious society — plus its humble nature promising perfection upon a kind of axial transcendence, as it becomes a Platonic solid in 4D.

Throughout history, the arms of London have used 3D effects on the red cross.

You can see the poised square three-dimensionality of the cross in London’s arms from a Tudor-era map of London prior to 1561 by Georg Braun and Frans Hogenberg (in Civitates Orbis Terrarum, 1572).

Old Sir Rowland Hill’s status as Sheriff and Lord Mayor of London, among other City roles, makes this symbolism very personal to him. The flag of the City of London still flies above Soulton Hall daily, as a reminder of Old Sir Rowland’s foundation of the building, and his profound importance to the City.

Old Sir Rowland was a great preserver of traditions, art, and institutions, as has been written about extensively elsewhere. Of particular note for Easter, however, is the Mercers’ Christ, a statue of the Corpus Christi (body of Jesus, entombed) that was buried for protection under the Mercers’ Chapel floor in London under Old Sir Rowland’s watch, during the Reformation.

Old Sir Rowland’s creation of an Aedicule meditation space at the heart of his home, next to his Prayer Room (recently restored by Tim Ashton), creates an Easter conversation over space.

The sacrifice of Christ occurs symbolically at one building Old Sir Rowland called home, and the Resurrection (the empty tomb) provided Christian hope at his country retreat.

A look back to Good Friday

There is another light effect at Soulton connected to Easter, which is that the staircase to the central Gallery of the Hall is lit by a west-facing window that has a single mullion and transom forming a cross.

The sun shines through this window down the stairs, projecting a striking silhouette of the cross, at roughly the time of the death of Jesus through the season of Good Friday (I mean, the range of dates from Computus).

What is important to understand is that the entire ‘drop’ of windows including this one was shifted by design a few feet to the south, butted up against the southwestern tower, to allow a partition wall to reduce the six-light window demanded by the balance of the building to a four-light window containing a cross. It takes some time to realise this from the outside, as the composition is otherwise so well balanced!

This shift prevents the western facade from being symmetrical, to add to the off-centre doorways of the north and south facades in making sure that divine symmetry marked-out the Aedicule facade as special — primed for a mathematical and meteorological allegory that evoked the Mystery and the hope of the Easter Sunday Resurrection.