Beheading Hero’s mechanical horse – an early ‘magical’ (nearly headless) automaton from Ancient Greece

by Paul Curzon, Queen Mary University of London

Stories of Ancient Greece abound with myths but also of amazing inventions. Some of the earliest automatons, mechanical precursors of robots, were created by the Ancient Greeks. Intended to delight and astound or be religious idols, they brought statues of animals and people to life. One story holds that Hero of Alexandria invented a magical, mechanical horse that not only moved and drank water, but was also impossible to behead. It just carried on drinking as you sliced a sword clean through its neck. The head remained solidly attached to body. Myth or Mystery? How could it be done?

The Ancient Greeks were clever. With many inventions we think of as modern, the Greeks got there first. They even invented the first known computer. Hero of Alexandria was one of the cleverest, an engineer and prolific inventor. Despite living in the first century, he invented the first known steam engine (long before the famous ones from the start of the industrial revolution), the first vending machine, a musical instrument that was the first wind-powered machine, and even the pantograph, a parallelogram structure used to make exact copies of drawings, enlarged or reduced. Did Hero invent a magical mechanical horse? He did, and you really could slice cleanly through its robotic neck with a sword, leaving the head in place.

Magic, myth and mystery

Queen Mary’s Peter McOwan* was fascinated by magic and especially Hero’s horse as a child, and was keen to build one. When TEMI, a European project was funded he had his chance. TEMI aimed to bring more showmanship, magic and mystery to schools to increase motivation. By making lessons more like detective work, solving mysteries, they can be lots more fun. The project needed lots of mysteries, just like Hero’s horse, and artist Tim Sargent was commissioned to recreate the horse.

If you’re ever in Athens, you can see a version of Hero’s horse, as well as many other Greek inventions at Kotsanas Museum of Ancient Greek Technology.

How does it work?

The challenge was to create a version that used only Ancient Greek technology – no electricity or electromagnets, only mechanical means like gears, bearings, levers, cogs and the like. It was actually done with a clever rotating wheel. As the sword slices through a gap in the neck, it always connects head and body together first in front, then behind the blade. Can you work out how it was done?

See a video of the mechanism in action below, with Peter introducing it.


This article was first published on the original CS4FN website and there is a copy in Issue 26 of the CS4FN magazine which is a memorial issue for *Peter McOwan, who died in June 2019. Peter, along with Paul Curzon, was one of the co-founders of CS4FN. You can download a free PDF copy of the magazine, called “Peter W McOwan: Serious Fun”, from our downloads site – along with copies of all of our other free material.


Related Magazine …


EPSRC supports this blog through research grant EP/W033615/1.

“The Truth About AI” – get ready to get tickets to the Ri Christmas Lectures 2023 #XmasLectures with @Ri_Science

Prof Mike Woolridge introduces this year’s Ri Christmas Lectures, on The Truth About AI.

Every year the Royal Institution (‘the Ri’) in London has a series of free Christmas Lectures for young people aged 11 to 17, and their parents or guardians. These lectures take place in the historic Faraday Lecture theatre and are (1) recorded live in mid-December and (2) live-streamed in various UK venues, then will be (3) broadcast on BBC Four over the Christmas holidays. The lectures will also be available on BBC iPlayer and live on the Ri’s lecture recordings page.

Grab a free ticket!

You can apply for free tickets when the ballot opens on 14th September.

“Due to their popularity, tickets to the filming are made available through a ballot open exclusively to Ri Young Members, Members and Patrons, as a thank you for their support throughout the year. Tickets are also made available for free to UK registered schools in disadvantaged communities.

The 2023 ballot opens on Thursday 14 September and closes on Wednesday 11 October.”

There are three recording sessions this year, all from 6pm to 8.30pm, on Tuesday 12, Thursday 14th and Saturday 16th December.

You can attend a livestream event

For those who don’t manage to get tickets there are lots of ‘overflow rooms‘ around the country, sharing the lectures as they’re being given – as a livestream. Queen Mary University of London (we’re based in Mile End) is one of them, but more venues around the country are being added. We’ll share more information in a few weeks about how you can get tickets for our own livestream events.

This year’s lecture

We think readers of this blog might particularly enjoy this year’s topic – “The Truth About AI” – which will be unveiled in a series of lectures given by Prof Mike Woolridge from Oxford University (Hertford College).

Photo credit: Paul Wilkinson

“Not since the World-Wide Web emerged 30 years ago has a new technology promised to change our world so fundamentally and so swiftly as AI does.  Today’s AI tools such as ChatGPT and AlphaGo are just a hint of what is to come. The future of AI is going to be quite a journey, and the 2023 CHRISTMAS LECTURES to be broadcast on BBC Four and iPlayer in late December, will give us a guided tour.

AI has increasingly grabbed the headlines in recent years – generating excitement and concern in equal measure – but what should we believe? In these lectures Mike will reveal how AI works and how it will affect our lives – and will tackle head-on our hopes and fears for this most fascinating of fields.”

read more at The Truth About AI

Our AI resources

We have a free AI booklet for young people which you can download as a PDF, and a classroom activity in which a piece of paper will probably beat you at noughts and crosses. Also plenty of our previous blog posts about artificial intelligence.

See if you can beat a piece of paper at noughts and crosses…

A classroom activity for teachers to try with their class is our Intelligent Piece of Paper activity. Can your class beat a piece of paper in a game of noughts and crosses aka tic tac toe?


EPSRC supports this blog through research grant EP/W033615/1.