Thursday, 2 October 2014

Recreating the methods used by Paolo Uccello in his mid 15th century painting The battle of San Romano.

Recreating the methods used by Paolo Uccello in his mid 15th century painting
The battle of San Romano.
By Paul F Walker
On June 1st 1432, 30 miles outside Florence, a small skirmish which we now as ‘The Battle of San Romano’ was fought between the forces of Florence and Siena. The Florantine Niccolò da Tolentino and Sienese Francesco Piccinino led the two opposing armies, which consisted of cavalry and infantry. The battle took the form of a series of cavalry charges that lasted for approximately seven hours and culminated in the defeat of the Sienese after the intervention of Micheletto Attendolo with a second Florentine cavalry force.

My version under candlelight.
The Battle of San Romano By Paolo Uccello mid 15th century

To commemorate the battle, the Bartolini Salimbeni family commissioned a set of three large paintings to be produced by Paolo Uccello. These large egg tempera paintings employed the newly discovered use of Perspective to give a sense of depth to the image with the traditional use of gold and silver leaf but in a highly innovative way.  The three images were completed between 1438–1440, and are housed at the National Gallery, London, The Galleria degli Uffizi, Florence and The Musée du Louvre, Paris. (Roy and Gordon 2001, 4-5)
Religious paintings used gold leaf to enhance the brilliance of halo’s and religious symbols but Uccello used the medium to depict the actual metal surfaces of the knight’s armour. This unusual use of metal leaf incorporated punched patterns and glazed shading which enhanced the overall effect.
In 2014, I made the decision to attempt to reproduce the methods used by Paolo Uccello. Previously I had made studies into the methods of 14th century Egg tempera paintings and Traditional 17th century methods in oil painting. I had also created illustrations specifically of armour throughout a 500-year period so the Uccello painting combined the use of all three techniques.
As I have, limited space, I chose to reproduce a small area situated on the right of the National Gallery painting, which depicts two clashing knights. I omitted the lance and the third knight depicted on a black horse choosing to simplify the composition to aid the visual effect.
Whilst the National gallery painting is rendered on a surface that consists of eight planks of poplar wood joined horizontally and reinforced with vertical strips of canvas my painting is on a single panel of poplar wood covered with fine canvas. (Roy and Gordon 2001, 6)
The original uses egg tempera and natural pigments with walnut oil and linseed oil glazes. Where traditional pigments are easily available, I have tried to recreate original colours, but in the interest of my health, some colours, such as lead white and yellow, are replaced by a safe chemical version.
The panel was first prepared with an undercoat or 'Size' made from gelatine which is created by boiling rawhide, this seals the panels grain and when dry a 'gesso ground’ is added.
 The gesso is made from 'Gypsum' mixed into the rawhide size (marble dust can be used), with the addition of titanium white powdered pigment. Traditional methods may have used lead white pigment but Uccello uses Gypsum.
The process of making the gesso involves gentle heating of the rawhide over a long period. (Up to four days), this process must be slow as rapid boiling will create bubbles, which ruins the paintings surface by leaving small pit marks.
On the fourth day of heating the size, the Gypsum is gently added and left overnight to cool. The gesso will set to the consistency of a firm jelly but will soften when reheated.
The first layer being rough known as the 'Gesso Grosso’, which, when dry, needs to be sanded, or 'Waterblocked' smooth. This method involves using a hardwood block that is planed perfectly smooth and flat. The block is simply dipped into water and rubbed in small circular motions across the panel to create a smooth surface. Four coats of gesso were applied and 'waterblocked' until the surface was smooth and flat becoming the 'Gesso Sottile'.
My version of the portrait depicting Mary of Burgundy, the fifteenth century, drawn in the same way as the San Romano depiction.
Traditional method of drawing used on smooth surfaces include pure soft metals, such as lead, which produces a pale grey line that is easily erasable.   Silver, Tin, Copper and various lead-and-pewter alloys were also used but all need a rough surface and are not erasable. Although the graphite pencil was not used until the end of the 16th century I felt that the drawing methods used would not be compromised by its use.
Uccello uses various aids to create sweeping lines and curves, one simple device being a compass to create the rounded backsides on the horses. His use of perspective is masterly and although very few of his drawings exist, those that do, are concerned with the changing shapes of objects in a three dimensional form.

Gilders Tip and Brushes

When the drawing was complete a red undercoat or 'Bole' made from clay, was added to the areas to be covered with gold or silver. This coating is to give a smooth hard surface to apply the leaf and give warm effect to the gold. The Size in the bole when wetted with alcohol acts as a glue, which holds the leaf.  The method of making bole is similar to creating the gesso but with red clay powder instead of gypsum. 
The ‘bole’ is laid down and smoothed using the same method as the gesso layer; patterning is then added by punching or scoring the surface. Various shaped tools were used to add details such as armour rivets and decoration on the crests. The outlines of the armour were scored with a sharp tool to aid the edging on the silver leaf.
When all the preparatory work was completed the armoured areas were covered with silver leaf and Gold leaf was used on the horse’s decoration and the helmet crests. (The original painting uses silver leaf on the crests).
The leaf is then added using a Gilders ‘Tip’, which is a flat brush of squirrel hair. (Badger hair is also used).
The leaf is incredibly thin, (four millionths of an inch) and just the slightest breath of air will send it blowing away. It is picked up with the Tip and laid down over the area to be covered, after a short drying period the loose leaf can be brushed away with a soft mop brush leaving the area clean. Any gaps or 'Faultings' can be filled with the small bits left over which are called 'Skewings'.

The area is then burnished with a flat rounded tool made from a polished agate stone; the stone can be rubbed on wax to aid the polishing process. The metal should now gleam but a polish with a soft cloth can bring it to a bright shine.
Shadowing was then added to the armour using a burnt umber pigment mixed with oils. This took the form of a glaze that was painted over the armour and removed from the highlights to show the silver leaf. Some of the graduated shading was achieved by dabbing with my fingers, a method used by Uccello which left fingerprints on the work. (Roy and Gordon 2001, 10)
The edging of the armour plates were then enhanced by lining with a fine brush using ink.  Various inks were available in the 15th century such as ‘Bistre’ which is made from the soot that coats the inside of a chimney. Uccello uses Indian ink, which I made from the soot of burned hardwood, traditional woods used were olive and grape vine. The burnt wood is ground down to a fine powder and mixed with vinegar, the mixture needs a binder such as gum Arabic but some woods such as pine contain resins that act as a binder.
When all the armour and gold leaf was complete and the lining dry, the Pigments for the painting were prepared by grinding the colours on a marble slab with a Muller. 

Uccello used colours which were made using various methods. Many colours were achieved using natural pigments, whilst others were chemically made using the technology of the period. In the battle of San Romano, Red lake, Vermilion, Ultramarine blue, lead tin yellow, azurite, yellow ochre, and a variety of natural browns are used. (Roy and Gordon 2001, 16).  The green foliage used 'Verdigris', a pigment that is made from copper. I have made this pigment but do not advise using it, as it is a long process and toxic. The method is simple and can be achieved with copper pipe cut into short lengths. The pipe is sanded clean and suspended  inside a sealable jar with white vinegar. The vinegar must not touch the pipe, as it is the vapour that reacts with the copper. The jar is sealed and put away for at least three months. At this point a green surface of crystals can be seen which when dried can be scrapped into a container and used.  A modern chemical version was used in my painting (for safety).
Other pigments In Uccello’s painting include 'Lead-tin' yellow. This is made by heating lead and tin oxides to various temperatures (Usually between 650 and 800 C) to create differing hues. Lower temps create more orange yellows whilst higher make lemon yellows. Again, I used a modern version.
These greens and yellows were painted on a charcoal black.
 The Blue pigment is Ultramarine mixed with lead white, Ultramarine pigment is made from Lapis lazuli which is a mineral that is mined in the valley of Kokcha in Afganistan. The process of making ultramarine involve grinding the stone into a very fine powder. This is then mixed with water and magnets are used to remove any pyrite particles. The fine powder is then mixed with wax and water and kneaded; this is then pushed through a fine cloth to remove any coarse grains leaving fine grade pigment.
Lead white is made in a similar method to verdigris but again is highly toxic and its manufacture is now banned.
The red pigment of the scabbard and saddle is Vermilion which was made from the mineral Cinnabar which is mined in Almaden, Spain. The mineral is ground heated and washed.
 The foreground horse is painted using white mixed with yellow ochre. Yellow ochre is a natural pigment which is made from clay that can be found throughout the world. The best shades being from Cyprus. The pigment is simply wetted and ground.
Roses and pomegranates use ‘Red lake’ glazes over white and a modern chemical version of Lead tetroxide.  Red lake is commonly known to be made from the cochineal beetle, but this was only used in Europe from the 16th century onwards after the Spanish imported from the new world. Uccello would have probably used Kermes Lake, which is a European form of the beetle that lives in Oak. The beetle would have been scraped from the branches of trees then ground and boiled; the solution is then filtered to remove any unwanted stuff and a solution of water and alum is added. The mixture now needs an alkali such as potash to form a reaction that precipitates the alum. The pigment will settle at the bottom of the mixture. After a process of repeatedly siphoning off the water and replacing it with clear water the pigment can finally be filtered and dried. The powder is then mixed with its medium.
The  Egg Tempera is made from the yolk of an egg mixed with a pigment. It can only be laid down in thin layers and has a very fast drying time thus the modelling of any shadow or form need to be built up from small brush strokes. 
The pigment is added to water and thoroughly mixed; it is then made smoother by grinding it with a Muller. The egg yolk is then separated from white and placed on an absorbent towel. (this removes the small amount of white that is left on the yolk sack. The yolk sack is gently pierced and the yolk added to the pigment mix and thinned to requirements. The amount of yolk in the mix can affect the overall finish with too much leaving a greasy finish and too little giving a chalky finish. The ideal being a slightly glossy finish. The paint can be bottled for use. 

Detail showing the texture caused by dabbing an oil based glaze over the armour. In areas my fingerprints could be made out, which to my surprise is seen on the original.

The paint was first applied to the panel in large areas of flat colour, using the body colour of each segment, Background, Horses, Saddles, Harness and scabbard.  This was then built up in small cross hatched brush strokes to describe highlight and shadow. This process requires patience and an ability to judge the underlying layers tonal quality as it is built upon using stronger colours. Areas of highly saturated colour such as the green in the foliage use glazes to deepen the shade and in Uccello’s original painting the addition of walnut oil to the egg tempera created an increased glossy surface and slowed the drying time.

 The overall effect of the silver leaf is most striking when viewed from different angles under candlelight  as the armour shines but unfortunately it cannot be shown easily in the photographs.

The completed work in daylight

Italian armour mid 15th century 
(a) Helmet (b)Visor (c) Gardbrace (d) Rerebrace/Uppercannon (e)Vambrace/Lowercannon (f) Gauntlet (g) Cuisse (h) Poleyn (i) Greave (j) Sabaton (k) Tasset (l) Fauld (m) Couter (n) Pauldron (o) Breastplate. (p) Mail skirt.

The Battle of San Romano

The Battle of San Romano was fought on June 1st 1432, some 30 miles outside Florence, between the troops of Florence, commanded by Niccolò da Tolentino, and Siena, under Francesco Piccinino. The outcome is generally considered favourable to the Florentines, but in the Sienese chronicles it was considered a victory. As the 1430s began Florence had found itself in conflict with the rival city state of Lucca, and her allies, Siena and Milan.

Watercolour painting of an armet with elaborate crest

The Florentine deployed about 4,000 horse and 2,000 infantry. The clash, which lasted for some six or seven hours, consisted of a series of heavy cavalry fights. It was decided by the intervention of a second cavalry corps commanded by Micheletto Attendolo.


The battle was depicted in three large paintings by the Italian Renaissance artist, Paolo Uccello: The Battle of San Romano. Today the three panels are separated and located in galleries in London, Paris, and Florence:

Armet with Visor removed .

Armet opened

A short History of the battle

The Battle of San Romano was fought on June 1st 1432 between Florentine and Sienese forces. Considered more of a skirmish in military terms the battle may have been forgotten had it not been for the commissioning of these three paintings by the Florentine Bartolini Salimbeni.  

Niccolò Mauruzi da Tolentino at the Battle of San Romano

The troops of Florence were commanded by Niccolò da Tolentino, Whilst the Sienese were under Francesco Piccinino. 

During the 1430's Florence was continually in conflict with the city state of Lucca, and her allies, Siena and Milan. The Florentines attacked with  approximately 4,000 mounted cavalry and 2,000 infantry  and  consisted of waves of cavalry charge and counter cavalry charge. which lasted for six to eight hours. Both Florentine and Sienese troops gaining little advantage until the intervention of troops commanded by Micheletto Attendolo. 

The outcome was favourable to the Florentines, who claimed to have won the battle but Sienese chronicles considered it to their advantage which only extended conflicts.

Paolo Uccelo or 'Paul the Bird' painted three stages of the battle from beginning to end. He depicts accurately, the armour of the 1440's, the cavalry being clad in the typical clean lines of Italian harness' with armet helmets  whilst trumpeters wear open faced sallets that have a nasal bar  that is hinged at the brow to allow the trumpet to move. Armoured foot soldiers can be seen as can crossbowmen.

Whilst the armour is accurately detailed Uccelo has chosen to depict the horses without protection. During this period it would have been more likely that heavily armoured  cavalry  would have had the same protection for their horses. Paolo has also chosen to show flamboyant crests on the helmets and the commanders without head protection, this would have been unlikely in such a battle and has confused art historians in the past who have incorrectly labelled the paintings as jousts.

Both sides are armed with lances, swords and war hammers.

To see photographs of Italian armour click here.

Niccolò Mauruzi da Tolentino strikes Bernardino della Ciarda with his lance 

The Counterattack of Michelotto da Cotignola

The battle was depicted in three large paintings originally having arched tops that fitted the rooms they were painted for. After the death of their commissioner the paintings were divided between the two sons but were soon acquired by Lorenzo de Medici who had them cut to fit  in his home the Palazzo Medici.  Today the three panels are situated in galleries in London, Paris, and Florence.

Reconstruction of Niccolò Mauruzi da Tolentino at the Battle of San Romano showing the original arched top.  Egg tempera with walnut oil and linseed oil on poplar, 182 x 320 cm


  1. In the painting rout of san romano there is a portion of a helmet on the ground located below the raised front hooves of the white horse. What portion of a helmet is that? What is the curved piece sticking out on the right side? You show something similar in your drawing above entitled Armet Opened. Is this the same thing I am asking about?

    1. Hi. The helmet you are asking about is complete and is a form of Barbute that had a hinged nasal guard. The curved piece is the guard. The curve and hinge made it easier for a horn to be blown as can be seen on the far left of the same painting. Hope that helps.

  2. Warfare is a fascinating subject. Despite the dubious morality of using violence to achieve personal or political aims. It remains that conflict has been used to do just that throughout recorded history.

    Your article is very well done, a good read.