The Definition And History Of The Lateen (Triangular) Sail

The Definition And History Of The Lateen (Triangular) Sail

Sailing, as we know it today, has been shaped by many developments and innovations throughout history. One of the most significant inventions that has helped to make sailing the sport it is today is the lateen sail. 

The lateen sail is identifiable by its triangular shape (see also ‘Why Are Sails Made In A Triangular Shape?‘) with a sloping yard that is longer than the other sides of the sail. 

These days, lateen sails (or the modernized versions, at least) are commonplace, but what exactly are they and how were they developed? That’s what we’re going to be exploring in today’s article. 

What Is The Lateen Sail? 

As previously mentioned, the lateen sail is a triangular sail where one side is secured to a sloping yard by each of its two corners. The third corner of the sail is secured to the sailboat close to the deck. 

Lateen sails, unlike some other sails, are mounted towards the middle of the mast, and the direction the sail runs in is known as ‘fore and aft’, which means that it runs both forwards and backwards, allowing it to withstand wind from both sides of the vessel.

Eventually, the lateen sail would be designed to allow ships using it to sail into the wind which, as we will find out over the course of this article, was instrumental in revolutionizing sailing. 

If you were wondering where the word ‘lateen’ comes from, it’s actually derived from ‘Latin’.

The reason for this is that the lateen sail’s origins have been pinpointed to the Mediterranean during the Roman era, although the invention really came into its own during the Age of Discovery. 

At the beginning of this article, we touched on the fact that the lateen sail is still used today. However, the version you’ll see on modern sailboats in the 21st century are modernized versions of the original design, known as crab claw sails.

We’ll be going into more detail about this later. For now, though, let’s explore the history of the lateen sail from the Roman era to the 14th century and beyond. 

The Lateen Sail’s History 

The Roman Empire 

If you’ve read through the article so far, you’ll already know that the lateen sail dates back to the Roman Empire. 

The lateen sail’s history actually begins with another kind of sail called the square sail rig. This is a type of rigging where multiple sails are mounted to a ship using horizontal spars. This was the design that inspired the evolution of the lateen rig. 

For a long time, it was unclear when exactly the lateen sail dated back to.

That was until a Belgian maritime historian named Lucian Basch pointed out that a Hellenistic painting from Alexandria dated at roughly the 1st century BC actually features a lateen rig, indicating that the lateen sail’s evolution dates back to at least this period in history. 

A lateen sail ship from roughly the year 400 AD has also been excavated, and the experts that helped to reconstruct the ship have stated that it’s likely the lateen sail’s existence extends further back than historical documentation would imply.

It is now thought that the lateen sail was actually developed by Muslim-led fleets before it began to be used in the Mediterranean. 

The 6th – 10th Centuries 

Until the 6th century AD, the square sail was the standard for sailors, hence the identification of the square sail rig as the starting point of the evolution of the lateen sail. 

However, by the end of the 6th century, the lateen sail had been established as the most effective type of sail, and it had almost completely replaced the original square sail, at least in the Mediterranean. 

The Byzantine dromon war gallery used the lateen sail as well, and considering that this ship has been hailed as the warship of greatest significance throughout the whole of the Byzantine period, this goes to show what an important innovation the lateen sail was. 

Various different navies around the world began using the lateen sail between the 6th century and the 10th century as the popularity of the hook-shaped masthead began to increase, showing that the lateen sail’s efficiency and benefits for sailing were beginning to become common knowledge. 

The 14th Century Onwards 

After the 14th century, the lateen sail continued to become established throughout the world. Baltic and Atlantic sailing vessels started using the lateen sail rather than the square sail from the 14th century onwards. 

During the late Middle Ages, the lateen sail became commonplace in Northern Europe as well. 

Contributions Of The Lateen Sail

Contributions Of The Lateen Sail

In the section above, we covered how the lateen sail evolved out of the square sail rig and spread throughout the world between the Roman era and the Middle Ages. 

However, we haven’t yet covered the reasons behind the massive surge in the popularity of the lateen sail and why it eventually replaced the square sail in navies worldwide. 

Here are some of the main reasons for the lateen sail’s popularity in terms of what this sail design contributed to sailing as a whole: 

Better Maneuverability 

One of the biggest advantages of the lateen sail over other sail designs, including the square sail rig, is that it allows for greater maneuverability. 

Being able to maneuver a ship efficiently, especially in challenging weather conditions, is extremely important, and so a sail’s ability to facilitate this is crucial. 

Part of the reason why lateen sails made maneuverability easier is that they allowed ships to sail closer to the wind, which meant that weather conditions were less of a problem when it came to altering the course of a ship. 

However, more than that, lateen sails also operated using a pulley or block system known as a halyard system, where lines run through the sail starting at the stern and going all the way up the mast and down to the stern again. 

Halyard systems were instrumental in allowing reefing, which is where the sail area is made smaller to reduce the power during strong winds. This made the experience of sailing much more flexible and safer overall. 

More Speed 

Lateen sails allowed ships to travel faster than the previous square sail rig design had done, especially in the case of Caravel ships.  

The faster speeds achieved by Caravel ships using lateen sails made excursions and explorations much easier and quicker. Sometimes, the lateen sail would be combined with the square sail, as Columbus did when crossing the Atlantic. 

Greater Load Bearing 

We mentioned earlier that lateen sails improved the maneuverability of ships, but this had more benefits than simply making it easier to steer.

One of the biggest advantages of the increased maneuverability provided by the lateen sail was that ships were now able to carry more cargo. 

When you think about it, this makes a lot of sense. Before the lateen sail, ships did not have as much flexibility when it came to changing speed or course.

This meant that in order to maximize the maneuverability of a ship, the crew would have to minimize the amount of cargo on board to ensure that the ship was as light as possible for the rowers. 

With the advent of the lateen sail, heavier cargo was able to be transported since the rowing ability of the crew was no longer the main factor.

Not only did this mean that ships could transport more food and other necessities during excursions, but it was also a major step forward for commercial empires such as Venice. 

Venice was able to become hugely successful as a European commercial empire because its use of lateen sail ships allowed for the transportation of products throughout the Mediterranean. 

Designed For Longer Distances 

Designed For Longer Distances 

Part of the reasoning behind the design of the lateen sail was that it allowed ships to travel longer distances since it meant that ships could sail closer to the wind and at faster speeds. 

In fact, countries such as Spain and Portugal relied on sea travel over long distances to increase their national statuses, and the lateen sail was an instrumental part of this.

Spanish and Portuguese ships would travel long distances to other countries so that they could trade goods from those countries and build status as a result. 

Enabled Land Discovery

We just discussed how the lateen sail’s increased speed and maneuverability allowed for travel by ship over longer distances, and how this allowed countries to build national status and grow through trade. 

However, this new ability to travel greater distances also enabled the discovery of countries and lands that had not yet been explored.

This is one of the main ways in which the lateen sail contributed to what is now known as the Age of Exploration, between the 1400s and 1600s. 

This period of history is called the Age of Exploration because this is the period in which nations throughout Europe began to use ships to go on excursions and explore the rest of the world, which is what led to the discovery of countries in the Far East as well as the Americas. 

Developments In Warfare 

In addition to land discovery, the benefits of the lateen sail that we have described so far (speed, maneuverability, load bearing and distance travel) all helped to create developments in the field of naval warfare. 

Naval ships needed to bring more supplies if they were going to war because it was unclear how long the ship would be at sea, so the ability to carry more was of the utmost importance.

Lateen sails were also able to improve the maneuverability and speeds of larger, heavier ships with cannons on board, which was why the Dutch, Spanish, French and English all used lateen sails for their fleets during the 19th century. 

This had a significant impact on the balance of political power during the Crusades. 

The Modernization Of The Lateen Sail 

The Crab Claw Sail 

We’ve already mentioned that while the lateen sail is still around today, it’s been modernized since its invention and is now usually known by a different name: the crab claw sail. 

It’s called the crab claw sail because it has a spar along the foot of the sail. This spar is aligned horizontally and connects to the mast. The joints in the sail spars have been designed to rotate in every direction for maximum flexibility. 

With this design, the sail sheet is connected to the spar at the bottom while the halyard connects to the spar at the top. The bottom spars stay parallel to the mast so that the sail forms a cone-shaped triangle. 

The Sunfish Sailboat 

Another difference between the lateen sail now compared to centuries ago is that lateen sails are now mainly used in smaller sailboats, typically those classified as recreational sailboats. 

Probably the most common example of a lateen sailboat in the modern day is the Sunfish, which is an individual-sized sailboat designed for personal use.

The modernized lateen sail on the Sunfish sailboat is attached to the mast and works using just one halyard, two lines, and of course, the sail sheet. 

These smaller, modern lateen sails are easy to work with and can be adjusted using a third line. This line can be used to pull on the lower spar so that it does down, creating tension in the other spars and allowing more control over the movements and positioning of the sail.

Final Thoughts 

The lateen sail has a fascinating history that spans from before the Roman Empire through the Middle Ages into the 19th century and, eventually, the modern day. 

This triangular sail revolutionized exploration, trading, and naval warfare by providing better speed, maneuverability, load bearing, and distance.

Countries were able to establish themselves and build status by fitting their fleets with lateen sails, and the use of these sails led to some of the greatest discoveries in history. 

Today, the lateen sail is better known as the crab claw sail and is used recreationally for smaller sailboats because of the simplicity and ease of use of its design.