The news has just come out that the Foursquare Exceptional Cask Selection (ECS) 2026 releases, the Mark XXX Penultimus and Mark XXXI Epilogue, will be the last two releases in what has been a fantastic run of rum bottlings developed by Richard Seale, the legendary fourth-generation rum distiller and blender. Find the ECS rum list below.
What Is the Foursquare Exceptional Cask Selection Series?
The Foursquare Exceptional Cask Selection (ECS) is a series of limited-edition premium rums from Foursquare Rum Distillery in Barbados. Each bottling is hand-selected and blended by master distiller Richard Seale.
Initally the bottlings would alternate between a vintage bottling and a bottling with an unusual or innovative cask maturation each year. Later in the series, there was often a vintage bottling and two of the cask matured bottlings per year. In some years, 2021, for example, there were four releases.
The ECS consists of single-blended rums made from a combination of pot still and column still distillates, produced entirely at Foursquare from molasses and tropically aged on-site in Barbados.

Key Features of the Exceptional Cask Selection
No additives: Richard’s ethos is that rum should be pure and “additive” free. There is zero added sugar or flavourings.
High Proof / Cask Strength many releases (often 56–62% ABV), though some are lower (e.g., 40–48%).
Innovative maturation: the ECS rum series is normally matured in ex-bourbon barrels followed by double maturation, finishes or blends involving ex-wine casks (for example, Port, Zinfandel, Madeira, Sherry, Cognac and even Black Muscat).
Limited but accessible: Released in batches of a few thousand up to 30,000 bottles, with no fixed schedule, only when Seale deems a batch truly exceptional.
Numbered “Marks”: Each gets a Roman numeral and often a Latin-inspired name.
When was the Foursquare Exceptional Cask Selection First Released
The Foursquare Exceptional Cask Selection was first launched with the Mark 1, a 1998 single vintage 10 year old bottling in 2008. I don’t remember this particular bottling, but I clearly remember the Mark II Port Cask and Mark VI Zinfandel Cask which were released in 2014 and 2015 respectively. It was these two bottlings that began to get rum aficionados really excited.
At the time, we were buying the ECS bottlings from Eaux de Vie Limited, Foursquare’s UK agents. They were eventually acquired by Marussia Beverages UK Ltd, who are the UK agents, and our suppliers, for Foursquare (and Doorly’s and RL Seale’s) today.
In those days, allocations were much more generous. The ECS rums had not developed their cult following, but demand was slowly building. It was not unusual for us to have 3 or 4 different ECS bottlings on the shelf at the same time.
Looking back at some old emails, I found an email from 2016 in which we were offering the Mark IV Zinfandel cask for sale at £36.99 a bottle. In 2026, the retail price is closer to £100 a bottle.
Have We Reached Peak ECS?
At the end of the 2010s, amongst our customers, interest in the exception cask series seemed to peak. At that time a lot of bottlings would also appear on auction sites straight after release and would sell for silly money. We wanted the bottles to go to people who would actually be drinking the rum, not flipping it on auction sites and began limiting purchases to one bottle per customer. I would say this really peaked during the time COVID – around the same time that the secondary whisky market was super-high too.
Eventually, we did not even put the releases on our website and they would still sell out quickly via word of mouth. However, as I write this in January 2026, we seem to have come full circle: we have two different ECS bottlings on the shelf, Mandamus and Convocation, and both are available to buy on the Fareham Wine Cellar website. So, perhaps it is timely that the series appears to be coming to an end.

What Next for Foursquare?
After the last two releases of ECS, Penultimus and Epilogue, it will be very interesting to see where Richard Seale goes next. No official new series or direct replacement has been announced yet by Foursquare or Richard. Perhaps there will be a shift to more unusual maturations or high-age expressions. It will be interesting to find out, and I am sure it won’t be boring!
The Complete Foursquare Exceptional Cask Series List
(As far as we know!)
2008
Mark I – 1998 Vintage – 10 Year Old, Bourbon Cask, 40% ABV
2014
Mark II – Port Cask Finish – 9 Year Old, 3 Year Bourbon, 6 Year Port Cask 40% ABV
2015
Mark III – 2004 Vintage – 11 Year Old, Bourbon Cask, 59% ABV
Mark IV – Zinfandel – 11 Year Old, Bourbon & Zinfandel Casks, 43% ABV
2017
Mark V – Criterion – 10 Year Old, 3 Year Bourbon, 7 Year Madeira, 56% ABV
Mark VI – 2005 Vintage – 12 Year Old, ex-Bourbon, 59% ABV
2018
Mark VII – Dominus – 10 Year old, ex-Bourbon, ex-Cognac, 56% ABV
Mark VIII – Premise – 10 Year Old, ex-Bourbon, ex-Sherry, 46% ABV
Mark IX – Empery – 14 Year Old, ex-Bourbon, ex-Sherry, 56% ABV
2019
Mark X – 2007 Vintage – 12 Year Old, ex-Bourbon, 59% ABV
Mark XI – Sagacity – 12 Year Old, ex-Bourbon, ex-Madeira, 48% ABV
Mark XII – Nobiliary – 14 Year Old, ex-Bourbon, 62% ABV
2020
Mark XIII – 2008 Vintage – 12 Year Old, ex-Bourbon, 60% ABV
Mark XIV – Détente – 10 Year Old, ex-Bourbon, ex-Port, 51% ABV
Mark XV – Redoubtable – 14 Year Old, ex-bourbon, ex-Madeira, 61% ABV
2021
Mark XVI – Shibboleth 16 Year Old, ex-Bourbon, 56% ABV
Mark XVII – 2009 Vintage – 12 Year Old, ex-Bourbon, 60% ABV
Mark XVIII – Indelible – 11 Year Old, ex-Bourbon, ex-Zinfandel 48% ABV
Mark XIX – Sovereignty – 14 Year Old, ex-Bourbon, ex-Sherry, 62% ABV
2022
Mark XX – Isonomy – 17 Year Old, ex-Bourbon, 58% ABV
Mark XXI – 2010 Vintage – 12 Year Old, ex-Bourbon, 60% ABV
Mark XXII – Touchstone – 14 Year Old, ex-Bourbon, ex-Cognac, 61% ABV
2023
Mark XXIII – Covenant – 18 Year Old, ex-Bourbon, 58% ABV
Mark XXIV – 2011 Vintage – 12 Year Old, ex-Bourbon, 60% ABV
Mark XXV – Equipoise – 14 Year Old, ex-Bourbon, ex-Calvados, 61% ABV
2024
Mark XXVI – Magisterium – 16 Year Old, ex-Bourbon, ex-Oloroso Sherry, 58% ABV
Mark XXVII – Equidem – 14 Year Old, ex-Bourbon, ex-Black Muscat, 61% ABV
Mark XXVIII – Convocation – 14 Year Old, ex-Bourbon, ex-Madeira, 62% ABV
2025
Mark XXIX – Mandamus – 16 Year Old, ex-Bourbon, ex-Tawny Port, 57%
2026
Mark XXX – Penultimus – 15 Year Old, ex-Bourbon, ex-Moscatel, 57% ABV
Mark XXXI – Epilogue – 19 year Old, ex-Bourbon, 57% ABV