The research article Greaney, S. et al. (2025) ‘Beginning of the circle? Revised chronologies for Flagstones and Alington Avenue, Dorchester, Dorset’, Antiquity, pp. 1–17. doi:10.15184/aqy.2025.28. published in Antiquity in 2025, presents significant new findings on the dating of proto-henges, particularly focusing on the Flagstones enclosure in Dorset, UK. Using an extensive radiocarbon dating program and Bayesian chronological modeling, the study provides a refined timeline for the construction and use of Flagstones and compares it to other key monuments like Stonehenge and Llandygai 'Henge' A.
Flagstones Enclosure
Construction Date: The Flagstones enclosure, a 100m-diameter circular monument made of intercutting pits, was constructed between 3315–3130 cal BC (95% probability), with a probable range of 3285–3215 cal BC (41%) or 3210–3160 cal BC (27%). This makes it one of the earliest precisely dated large circular enclosures in Britain.
Funerary Activity: Burial activity, including inhumations and cremations, began shortly after construction, estimated at 3265–3105 cal BC (95% probability), probably 3230–3220 cal BC (4%) or 3205–3120 cal BC (64%), and ended between 3220–3065 cal BC (95% probability), probably 3150–3090 cal BC (68%). This activity spanned a relatively short period of 1–170 years (95% probability), suggesting it may have been part of the site’s initial dedication.
Context: Flagstones predates the nearby Mount Pleasant henge (built 2615–2495 cal BC) by several centuries and is closer in time to Early Neolithic monuments like the Maiden Castle causewayed enclosure (3660–3635 cal BC or 3570–3525 cal BC) and the Alington Avenue long enclosure (before 3625–3380 cal BC).
Alington Avenue
Construction Date: New radiocarbon dates from a cattle skull in the northern ditch of the Alington Avenue long enclosure indicate it was built before 3625–3380 cal BC (95% probability), probably before 3605–3405 cal BC (68%). This places it 110–470 years (95% probability) earlier than Flagstones, marking it as an earlier linear monument in the Dorchester complex.
Comparison with Other Proto-Henges
Stonehenge: The first phase of Stonehenge, a segmented circular ditch, is dated to 2980–2720 cal BC (95% probability), probably 2940–2800 cal BC (68%), making Flagstones 70–285 years earlier (95% probability). Cremation burials at Stonehenge began in 3075–2945 cal BC and ended in 2890–2765 cal BC, later than those at Flagstones.
Llandygai 'Henge' A: Funerary activity at this 80m-diameter enclosure started in 3655–3345 cal BC and ended in 3075–2715 cal BC, earlier than Flagstones’ construction, though the enclosure itself lacks direct dating. This suggests a longer tradition of circular monument use in some regions.
Stones of Stenness (Orkney): Previously considered one of the earliest henges, its ditch dates to 3035–2895 cal BC, later than Flagstones, reinforcing Flagstones’ claim as an early example.
Broader Implications
Earliest Circular Enclosure?: Flagstones may be the earliest large circular enclosure in Britain with precise dating, predating Stonehenge and other candidates like the Stones of Stenness. Other potential early sites (e.g., Ysceifiog, Priddy Circles) lack sufficient excavation or dating to challenge this.
Transition to Circular Forms: The study highlights Flagstones as a key marker in the shift from linear (e.g., long barrows, cursus monuments) to circular monument archetypes in the Middle Neolithic (3400–2800 cal BC), bridging earlier causewayed enclosures and later henges.
Funerary Practices: The mix of inhumations and cremations at Flagstones reflects an early phase in the transition to cremation rites, paralleled at Stonehenge and Llandygai, and tied to smaller ringform enclosures (dated 3960–3400 cal BC to 3265–2605 cal BC).
Significance
This research refines the chronology of proto-henges, positioning Flagstones as a pioneering circular monument that influenced later developments, such as Stonehenge. It underscores continuities with Early Neolithic practices (e.g., pit construction) while introducing innovations like large circular forms and cremation burials, possibly inspired by connections with eastern Ireland. The precise dating enhances our understanding of the Middle Neolithic’s monumental landscape and its cultural transitions in Britain.