Site & dates
The Tower of Naillac › Eastern tip of the Mole of the Windmills
The Tower of Naillac stood at the eastern tip of the Mole of the Windmills, the breakwater that separates Mandraki, the Order's war-galley harbour, from the Commercial Harbour, the working merchant port, to its south-east. Built in 1400 under Grand Master Philibert de Naillac, it combined a fortress commanding the only navigable entrance into the Commercial Harbour, a lighthouse guiding shipping into port by night, and the anchor point for an iron chain that could close the harbour mouth outright. Nothing of this medieval structure survives above the waterline: it was totally destroyed in the earthquake of 1863, and what stands at the site today is a later, twentieth-century corner tower built beside the one surviving medieval fragment, an entrance arch.
A tower known only at second hand
What survives › an arch, a staircase tower, and submerged foundations
Unlike most monuments in this project, almost nothing of the Tower of Naillac's own medieval fabric can be examined directly. Its original structure is known only through the restoration literature, early photography, and a separately consulted institutional history, while the two elements standing at its site today belong to two different, much later building campaigns -- one medieval, one twentieth-century -- that this document is careful not to conflate.
Fortress, lighthouse, and chain
1377–2025 › from Heredia’s quay to a digital twin
The Tower of Naillac's history runs in two distinct phases: four and a half centuries as a working harbour fortification, built and repeatedly rebuilt across the Order's successive Grand Masters, and then, after its destruction in 1863, a century and a half as an absence -- a famous name attached to a site where almost nothing of the named structure remains.
Architects narrate
Manoussou-Della, Shabani & Karimi, and Abercrombie › direct testimony
“The main tower of the fortifications for the defence of the harbours.” — the restoration-works literature's own description of the Tower of Naillac at the height of its working life, before its destruction in 1863.
“The main symbol of the bustling and cosmopolitan commercial harbour of the city” — a landmark known during Ottoman rule, in the same source's words, as the ‘tower of the knights.’
A finite-element structural model of the corner tower and arch, calibrated against ambient-vibration testing from 736 ground photographs, 1,117 drone images and 38 terrestrial laser scans, identified the structure's first two natural frequencies at 5.981 Hz and 9.253 Hz, with an absolute calibration difference of less than 0.03 percent — and found the tower's actual elastic modulus more than three times higher than empirical equations alone would predict.
A materially different account of the tower's own origins: that it was dedicated, when built, to Saint Michael; that its four walls met at right angles rather than forming an octagon; and that it was designed, in the words of this institutional source, before siege artillery had come into wide use — a design logic this document's other sources do not address.
Six Grand Masters and two earthquakes
1377–1534 › the tower’s own cast of named figures
Six Grand Masters, across more than a century, run through the documentary record of this monument's construction and repair, alongside the two sieges and two earthquakes that mark the turning points of its working life and its eventual loss.
The Tower That Outlived Its Own Name
1400 – 1863 › a narrative reconstruction for visitors
Philibert de Naillac becomes Grand Master of the Hospitallers in 1396, inheriting from his predecessor Juan Fernandez Heredia a harbour mouth already part-fortified: a quay reinforced, a Byzantine sea gate reworked, the first towers raised against both weather and raiders. Naillac finishes the work his predecessor began, and by the turn of the century a single great tower rises at the eastern tip of the mole that will one day bear the windmills' name. The restoration literature consulted for this document calls it octagonal and dates its completion to 1400. A separately consulted institutional history of the Order's Grand Masters tells a different story in its particulars: that the tower was dedicated, when new, to Saint Michael the Archangel, patron of soldiers and sailors alike; that its four walls met at right angles rather than curving into an octagon; and that it was completed not in 1400 but early in the following year, 1401, designed -- this source stresses -- in an age before siege artillery had come into wide use, when thick walls and a commanding height still counted for more than a sloped, cannon-resistant profile. This document reports both accounts rather than choosing between them.
Whatever its exact shape and year, the tower that rose at the harbour mouth did three jobs at once, in a combination the restoration literature treats as characteristic of the Order's harbour-defence building. By day and by night it stood as a fortress commanding the only navigable entrance into the Commercial Harbour below. By night alone it served a second, civil purpose, as a lighthouse guiding merchant shipping into port. And at its base, fitted -- the sources say -- 'with great certainty' by Naillac himself, sat the fixed end and control mechanism of an iron chain that could be run across the harbour mouth to the mole's far side, closing the port outright. Each evening, so a modern engineering study of the site records, the chain was drawn across the water; each morning it was lowered again, and Rhodes' merchant trade resumed.
A separately consulted institutional history closes its account of Naillac's building work with a single further, hard-to-verify but suggestive detail: that the tower was completed in the fifth year of his magistracy, and that in the same period of his rule, Naillac is credited with ordering the fortification of the Castle of Saint Peter at Halicarnassus -- the site known today as Bodrum, on the Anatolian mainland facing Rhodes across the water. Read together, the two projects suggest a Grand Master thinking in pairs: a tower to guard his own capital's harbour mouth, and a castle to secure the Order's foothold on the coast opposite it -- though this document notes that the Halicarnassus detail is reported here as this one institutional source presents it, and has not been independently corroborated against the restoration literature consulted for the Tower of Naillac itself.
The tower that took Naillac's name outlived him by more than four centuries, through sieges in 1480 and 1522, through the change from Hospitaller to Ottoman rule -- and then, in the space of twelve years, it did not. In 1851 an earthquake brought down its upper storey; by May of the following year a photograph shows it repaired, restored, apparently whole again. The repair did not last. A second, more violent earthquake in 1863 brought the entire structure down, leaving nothing above the waterline but a single stone archway that had once led visitors inside, and foundations that still lie submerged at the mole's tip today. Half a century later, during the Italian administration of Rhodes, a modest new tower was built beside that surviving arch -- not to defend anything, but simply to carry a staircase. It is this small, unrelated, twentieth-century structure that most visitors now photograph and call 'the Tower of Naillac' -- a famous name, attached, for want of anything closer, to a building Naillac never saw.
The Legendary Tower
Nine views › prints, photographs, and the Caoursin manuscript — the Tower of Naillac and the Tower of France identified at the harbour mouth as supplied
Significance criteria
Nine-criteria framework › International importance
Statement of significance
“The main symbol of the bustling and cosmopolitan commercial harbour of the city.” (K. Manoussou-Della, on the Tower of Naillac at the height of its working life.)
The Tower of Naillac was, for over four centuries, the principal fortified landmark of Rhodes' Commercial Harbour: built in 1400 (or, per a separately consulted institutional history, early 1401) under Grand Master Philibert de Naillac at the eastern tip of the Mole of the Windmills, it combined a fortress commanding the harbour mouth, a lighthouse guiding shipping into port, and the anchor point for a harbour-closing chain fitted, on the restoration literature's own assessment, 'with great certainty' by Naillac himself.
The tower did not survive in the present. Its upper storey collapsed in the earthquake of 1851 and was repaired by 1852, but a subsequent, more catastrophic earthquake in 1863 destroyed it in its entirety, leaving only its foundations submerged beneath the sea. Only a medieval entrance arch survives from the original structure; the corner tower most visitors see and photograph today at the site was built during the Italian administration (1912-1947) to house a staircase, and is not a reconstruction of Naillac's tower. This document presents that distinction explicitly throughout, and flags for reconciliation its own discrepancies, between the restoration literature and a separately consulted institutional history, over the tower's original dedication, completion date, plan and height.
A monument known almost entirely at second hand, whose own fabric cannot be examined directly, in contrast to the better-preserved gates and walls documented elsewhere in this project. What remains open, and is reported as such throughout, is the precise shape, height and completion date of the lost original tower; the identity of its companion tower on the harbour's opposite side, named as the Tower of France in the gallery images supplied for this document but not independently corroborated in the restoration literature otherwise consulted; and the correct reconciliation of this document's account with this project's own companion Statement for the Commercial Harbour.
Taken together, these qualities give the Tower of Naillac significance of International importance: an integral component, linking the Military Harbour (Mandraki) and the Commercial Harbour, of the Outstanding Universal Value of the UNESCO-inscribed Medieval City of Rhodes, notwithstanding the low physical integrity of the original medieval structure it commemorates in name alone.
Hellenic Republic: ΥΑ 23084/737/25-8-1948 — ΦΕΚ 10/23-9-1948 (Ministerial Decision declaring the monuments of the Medieval Town of Rhodes, including the Tower of Naillac's surviving medieval entrance arch and the adjoining Italian-era corner tower, protected under Greek Archaeological Law; subsequently confirmed under Law 3028/2002).
World Heritage property: Medieval City of Rhodes (ref. 493), inscribed 1988, meeting criteria (ii), (iv) and (v). The Tower of Naillac's site forms part of the fortified circuit cited in the property's Statement of Outstanding Universal Value, alongside the Palace of the Grand Master, the Great Hospital, Mandraki and the Commercial Harbour.
References
- Manoussou-Della, K. ‘I. Detailed description of the fortified perimeter during the siege of 1480 — Ia. Sea section of the fortifications — Ia.1 The great commercial harbour of the town of Rhodes’ (in Greek), pp. 184–202. This document's principal academic source for the Tower of Naillac's building and restoration history and the harbour-mouth chain; no cover or title page was included in the extract consulted for this project, so the parent chapter/volume's full title, publisher and year are not independently confirmed. Cited in the text as 'Manoussou-Della, Commercial Port.'
- Manoussou-Della, K. Morphological Elements of the Medieval Gates of the Town of Rhodes, pp. 218–242. Full journal/volume title, publisher and year not fully captured in the working extract consulted for this project; cited in the text as 'Manoussou-Della.'
- Della, A., and D. Dellas. Restoration works report on the Gate of Amboise and related Commercial Harbour-front fortifications (Tower of Naillac, Marine Gate, Gate of St Paul, Tarsanas Gate), in the compiled restoration-works volume for the Medieval Town of Rhodes, 2000–2008 (pp. 79–147, 600, 119). Cited in the text as 'Della/Dellas.'
- Shabani, Amirhosein, and Amir Hossein Karimi. ‘Operational Modal Analysis and Finite Element Model Updating of the Naillac Tower in Rhodes, Greece.’ In The 1st International Conference on Net-Zero Built Environment, edited by M. Kioumarsi and B. Shafei, 1335–1345. Lecture Notes in Civil Engineering vol. 237. Cham: Springer, 2025. DOI 10.1007/978-3-031-69626-8_112, Open Access CC BY 4.0. This document's critical new source for the 1863 total destruction of the original tower and the true nature of the surviving Italian-era corner tower; cited throughout as 'Shabani and Karimi.'
- Abercrombie, G.E. The Hospitaller Knights of St John in Rhodes 1306-1522. Barnsley, UK: Pen and Sword, 2024. Chapter 9, 'Philibert de Naillac, 1395-1421,' consulted for this document's account of the tower's original dedication to Saint Michael, its completion date and pre-artillery design, and Naillac's parallel fortification of the Castle of Saint Peter at Halicarnassus; this document flags that this source's figures for the tower's plan and height differ from the restoration literature consulted elsewhere -- see Fabric and Story, above, for this discrepancy reported plainly rather than resolved.
- Manoussou_Della, K. ‘Le Paysage Culturel et Les Monuments Symbols Disparus de la Ville de Rhodes.’ Europa Nostra Bulletin Scientifique (2012): 59–74. Known to this document only via its citation inside Shabani and Karimi (2025); not independently read.
- Vatin, Claude. Rhodes et l'ordre de Saint-Jean-de-Jérusalem. Paris: CNRS Éditions, 2000. Known to this document only via its citation inside Shabani and Karimi (2025); not independently read.
- Karousos, Christos. Rhodes: History, Monuments, Art (Ancient Sites and Sanctuaries of Greece). Esperos Editions, 1973. Known to this document only via its citation inside Shabani and Karimi (2025), as the source of a historic drawing of the old Naillac tower and arch; not independently read.
- Mercieca, Simon. ‘Maritime Caravans and the Knights of St John: Aspects of Mediterranean Seaborne Traffic (Sixteenth–Eighteenth Centuries).’ Chapter 8 in Trade and Cultural Exchange in the Early Modern Mediterranean: Braudel's Maritime Legacy, edited by Maria Fusaro, Colin Heywood, and Mohamed-Salah Omri, 158–175. London: Tauris Academic Studies. Read directly for this project and found to concern the Order's later, Malta-period 'caravan' institution rather than Rhodes' harbour architecture; it does not corroborate the Tower of Naillac, 'Tower of St Angelo,' or Commercial Harbour chain identifications -- see Fabric, above.
- Bronstein, Judith. ‘The Hospitallers: From Land to Sea — An Examination of the Hospitallers' Naval Activities in the Twelfth and Thirteenth Centuries.’ The Medieval History Journal 22, no. 1 (2019): 53–91.
- Jacoby, David. ‘Hospitaller Ships and Transportation across the Mediterranean.’ Chapter 6 in The Hospitallers, the Mediterranean and Europe, pp. 57–72. Full editor, publisher and year not captured in the working extract consulted for this project.
- Vidoni, Tullio. 'The Journal of Roberto da Sanseverino (1417-1487): A Study on Navigation and Seafaring in the Fifteenth Century.' PhD dissertation, University of British Columbia, 1993; and Sanseverino, Roberto da. Viaggio in Terra Santa, ed. Gioacchino Maruffi (Bologna, 1888). Both reviewed for this project; neither contains content specific to the Tower of Naillac.
- UNESCO World Heritage Centre. “Medieval City of Rhodes.” World Heritage List, ref. 493. Inscribed 1988.
- ICOMOS. ICOMOS Charter for the Interpretation and Presentation of Cultural Heritage Sites. Paris: ICOMOS, 2008.
- ICOMOS Australia. The Burra Charter: The Australia ICOMOS Charter for Places of Cultural Significance, 2013.
- Hellenic Government Gazette (ΦΕΚ). Ministerial Decision 23084/737 (25 August 1948), ΦΕΚ 10 (23 September 1948), protection of the monuments of the Medieval Town of Rhodes; Law 3028/2002 on the Protection of Antiquities and Cultural Heritage in General.
- Manousou-Della, and George Dellas. 'The Eastern District of the Burgh of Rhodes.' 2019. Cited for comparative commercial-topography evidence from the wider harbour-front district.
- Kasdagli, Anna-Maria, and Katerina Manoussou-Ntella. 'Health Care in Hospitaller Rhodes, 1309-1522: Practices, Organization and Location.' 2022. Cited for general Hospitaller-era institutional background.
- Manoussou-Ntella, Katerina. 'The Byzantine Fortification and the Magna et Communis Platea.' 2022. Cited for the topographical setting of the harbour-front district.
- Phillips, Simon David. Rhodes in the Final Hospitaller Years, 1502–1521: Latin and Greek Interaction in the Aegean and Eastern Mediterranean. PhD dissertation, National and Kapodistrian University of Athens, 2021.
- Setton, Kenneth M. Jem Sultan. In The Papacy and the Levant, vol. 2. Philadelphia: American Philosophical Society, 1978.
- Setton, Kenneth M. The Fall of Rhodes, 1522. Cited for the 1522 siege's aftermath.
- Setton, Kenneth M. The First Siege of Rhodes. In The Papacy and the Levant, vol. 2. Philadelphia: American Philosophical Society, 1978. Cited for the 1480 siege.
- Vaivre, Jean-Bernard de. ‘Sur quelques monuments de Rhodes.’ Comptes rendus des séances de l'Académie des Inscriptions et Belles-Lettres 153, no. 1 (2009).
- Vertot, René Aubert de. The History of the Knights Hospitallers of St. John of Jerusalem. 5 vols. 1757 English edition. A secondary, literary source written more than two centuries after the events described, and treated throughout as such rather than as documentary evidence.
- Nine gallery images for this document were supplied directly by the user: a hand-coloured historic city view, a nineteenth-century engraving, four modern photographs of the surviving site, a captioned historic photograph of the separate Fort of St Nicholas, and three illuminated-manuscript miniatures from Guillaume Caoursin's chronicle of the 1480 siege, Bibliothèque nationale de France, Département des Manuscrits, Latin 6067 (source: gallica.bnf.fr). Individual attributions and this document's own identification of the Tower of Naillac within the manuscript images are given in each image's own caption in Gallery, above.
- REBOOT Statement of Significance: Commercial Harbour, Rhodes (2026) -- companion document for the harbour the Tower of Naillac guarded; this document flags its own, superseding account of the tower's 1863 total collapse against that Statement's reliance on the 1852 repair alone, per Fabric and the Statement of Significance, above.
- REBOOT Statement of Significance: Mandraki (Military Harbour), Rhodes (2026) -- companion document for the war-galley harbour on the Mole of the Windmills' opposite side from the Commercial Harbour.
- REBOOT Statement of Significance: Gate of Emery d'Amboise, Rhodes (2026) -- cross-referenced for G.E. Abercrombie, The Hospitaller Knights of St John in Rhodes 1306-1522, as a source also consulted for that monument's Statement.