Glass, from Egyptian or early Roman times, is often seen today as far more ornate and complex than glassware produced in the centuries following the Christ event. The Romans, by the first century, had become very proficient at glass production and also used lead to strengthen it. Most archaeological evidence of glass mirror dates from the third century in Egypt, Gaul, Asia Minor and Germany.
Digs in Egypt have uncovered mirrors that have glass with a convex curve behind lead over which a coating of gold or tin had been applied. Variations on this process prevailed for centuries.
Following the sack of Rome by the Visigoths in the fourth century and, for over a thousand years the glass industry remained, but only as limited trade. By 476 continual invasions and migrations of Germanic tribes ended imperial rule in the West and led to the creation of separate states such as Germany, Gaul, Britain, Spain, North Africa and Italy.
In the East, at Constantinople, Roman imperial culture continued, but it would evolve with little interference in a form now generally referred to as Byzantine. After 632 the armies of Islam conquered Syria, Palestine, Egypt, the coast of North Africa ending Byzantine rule.
Islam absorbed the Roman, Byzantine, Coptic and Sassanid cultures and developed their own decorative style
Egypt’s most important contribution to the art of glass in Islamic times was developing lustre painting techniques. This involved firing a film of pigment onto the surface of the glass. Like ceramics, metallic compounds such as silver, copper or gold oxides dissolved in acid were painted onto the cold glass surface with an oily medium and then fired in a reducing furnace atmosphere. The resultant carbon monoxide helped enhance the metallic lustre so that the decoration glowed gloriously.
Small glass-factories survived throughout the Middle Ages in Europe because they were set deep in the forests so that they could gain enough timber to feed their furnaces, which needed to be heated in excess of 1000 degrees Fahrenheit. Today 2000 degrees is more the norm.
From the twelfth century onward skilled glass workers extended the colour palette to provide coloured glass, which would then be outlined in lead and set into the windows of great Gothic cathedrals and churches. A brilliant blue and a wonderful peach were dominant colours, the latter made through the addition of gold.
Exploitation of light in the east was always through carved tracery of stone made possible because of climatic conditions. To introduce an optimum amount of light in Europe, where the climate had a preponderance of dull days, became a fresh challenge. It also became a goal of all early architects of civic buildings,
When Abbot Suger set about rebuilding the Abbey at St. Denis (right) near Paris during the eleventh century the golden age of Gothic architecture and glass stained with colour began.
Neo-Platonic theory, to which Abbot Suger subscribed meant that he needed to produce a style of architecture lit by ‘radiant windows’ to, as he said, ‘illumine men’s minds so they may travel through it to an apprehension of God’s light’.
Before the advent of this uniquely Christian art form windows were only utilitarian. In fact they had evolved from slits in the walls of a keep to shoot arrows through into being much larger ‘wind eyes’. While they provided light and air for the poor, it was only the wealthy who could afford to have them glazed. The rest made do with covering them with plaited rushes or the like when it was cold.
Great expanses of glass became a hallmark of Gothic architecture and a mark of God’s continually improving status.
Further experimentation opened up the development of this extraordinary material. Monks like Suger were aware coloured glass not only sent an image of deep spirituality but also drew the faithful to read the messages of the stories it told because it dazzled them with its radiance. One can only try to imagine the effect of such brilliance on a mind emerging from a state of written illiteracy, which must have been quite staggering.
Going to church for medieval people meant receiving inner spiritual instruction and comfort as well as entry into a magical kingdom where a mystical experience made man more receptive to God. A contrast in our own day would be special effects offered in the movie cinemas of the world where we can be transported to another world, forget our difficulties, mind numbing challenges and enjoy a break from the humdrum reality of everyday life.
Some beautiful drinking horns of blue glass survive from the Medieval period of north western Europe. The Sutri Drinking Horn in the British Museum is a fine example of a shape first made in antiquity from metal.
Thin opaque white trails spiral around the body of the vessel, while the thicker blue trails have been scalloped and the rim is faintly marked by pincers.
The horn was a unique discovery and obviously one its original owner cherished because it was buried so he would have something wonderful to drink from in the afterlife.
During the twelfth century a monk named Théophile recorded contemporary glass making techniques.
This was at a time when commentators viewed science and the supernatural as intimately linked. The transformation of half solid, half liquid, molten glass into a transparent and rigid substance was viewed as some sort of magic or alchemy.
In his writing Théophile refers to French glass makers as masters of the art and provides a recipe….two parts beech tree ashes to one part sand.
Their methods of glass blowing involved procedures he states ‘as inherited from the ancients’.
The technique of applying a silvered backing to mirrors also began to evolve slowly and from the thirteenth century small mirrors were being exported to Genoa and from there all over the Mediterranean world. In Germany enameled decoration on glass remained popular for hundreds of years.
This type of large beaker is called a Humpen, from a word meaning a tankard, although without a handle.
Guests were offered a drink on arrival as a mark of hospitality. They were then expected to drink the entire contents of the glass in one go.
Some vessels held up to four litres of beer so for many it was quite a challenge. Humpen were held in both hands and passed around for drinking toasts at banquets. The glass on the left in our pair was painted in 1594 and bears the image of a double-headed imperial eagle, who represented the alliance of nations known as the Holy Roman Empire.
German glass making centers at Bohemia, Saxony, Silesia and Potsdam were expanding. And, by about 1680 a new formula to improve glass was discovered. Chalk was added to the mix and potash replaced soda; the resultant glass had a hard brilliance that was far better suited to developing deep cutting techniques.
The origins of the Venetian glass industry remain obscure although there are many hypothesis. A great many exquisite specimens of Roman glass have been excavated at Aquilea, which is midway between Venice and Trieste.
Tradition has it that glass workers, fleeing from the northern ‘barbarian’ invaders of the fifth and sixth centuries in Europe, hid out with other people on a group of barren marshy islands in the north of Italy, which were set in a lagoon. These were the people who founded the city of Venice.
The first Venetian glass maker to figure in documentary records is a Benedictine monk, Domenico. In records from 982 he is described as a fiolario, a maker of phials which were used for storing medicaments. We can only hypothesize the technique used for blowing glass because we have no documentary proof.
At this time Venice was closely allied with Byzantium, where the remains of the classical Roman world had been preserved.
The conquest of its capital Constantinople in 1204 by the wayward Fourth Crusade was a watershed event. It opened Venice up to the practices of their glass producers whose skills had been passed down from original Roman workers.
Over the ensuing centuries glass artisans of Venice expanded their skills in glass production and, by 1255 there were enough craftsmen in Venice to form a guild. Glass blowing techniques were refined also through trading contacts with the Orient and, above all with countries who shared an ancient tradition in glass blowing, such as Syria and Egypt.
By 1291 the glass makers of the Venetian lagoon had distilled that knowledge into their own unique and proprietary glass making production skills. In the same year the government of Venice banned furnaces from the central islands and relegated them to one, the island of Murano.
Many early historians assume a fear of fires from furnaces might create a tragic conflagration among the largely wooden structures of the then overcrowded Venice. However, it has been plausibly suggested the move was meant to isolate master glassblowers to prevent them sharing their know how with foreigners.
From that time onward glassblowers were insulated and isolated from contact with those who might divulge their production secrets to potential competitors abroad.
In this way Venetian, or Murano glass making became the leading source for fine glass wares in Europe and a major source of trading income for the Republic of Venice. This condition lasted for three centuries. Venetians were certainly the first to make completely transparent glass since the days of the Roman Empire and their so-called cristallo became famous.
The glass was blown until it was amazingly thin and worked it into a bewilderment of shapes. Today those that survive take your breath away with the beauty of their form and imaginative genius of their makers.
A high water mark in the production of the finest glass, Cristallo, was reached in both technique and style with the so- called Flugelglas, the most extravagant expression of the Venetian style. Most of the glass made in Venice, although luxurious, was also utilitarian.
The glass making phenomenon that occurred at Murano made its presence felt with an increasing demand for luxury glass.
England and the other emerging centres of the Holy Roman Empire, which encompassed almost the whole of Central Europe at that time, including the low countries, Belgium Luxembourg and the Netherlands, were entirely captivated by the Venetian style.
The German-speaking world was also active in the field of engraving on both glass and rock crystal, especially the glasshouses at Prague and Nuremberg. A parcel gilt mounted rock crystal goblet (left) was made late in the sixteenth century and engraved in 1630 by Schwanhardt the Elder. He developed a special technique that enabled him to polish wheel engraved decoration restoring light and life to the engraved areas of the vessel.
This technique also transposed to glass and as the popularity of Cristallo increased, the ductile qualities of glass came to be appreciated.
By the 1600s rival centers began to emerge, notably in France and Moravia. At the same time shifting trade routes,. such as the Netherlands, began to undermine Venice’s strategic trading advantage.
As a result, the decline in Venice’s general political and commercial importance after 1600 was mirrored by the gradual and long-term decline of its glass industry.
The earliest glass discovered in Britain also dates from Roman times. It is unclear whether it was imported or Roman glass makers had set up furnaces in that place. No Roman glasshouse sites of the period have come to light, at least yet. The Venerable Bede in his Ecclesiastical History wrote in 675 that
‘Benedict Biscop sent messengers to Gaul to fetch makers of glass who were unknown in Britain at this time, that they might glaze the windows of his church’.
Cuthbert, Bishop of Jarrow wrote to Lullus, Bishop of Mayence in 758 to
‘beg your fraternity that you will persuade any man in your diocese who can make vessels of glass, to come to us for we are ignorant and helpless in that art’.
Venetian maker Jacopo Verzelini was bought to England by Huguenot Jean Carré to improve the quality of glass being produced at his London workshop. After a troubled start Verzelini acquired royal patronage in 1575 when Queen Elizabeth granted him a licence
‘to make drinking glasses in the manner of Murano, on the undertaking that he bring up in the said art and knowledge our natural subjects’.
Verzelini kept the bargain and during the twenty years that followed he made much fine glass, a good deal of money and won a great deal of respect.
He set up a successful glasshouse in Britain, at Crutched Friars in London. This superb goblet has been attributed to Verzelini’s glasshouse by curators at the V & A Museum because of its diamond-point engraved inscription and its quality.
The inscription ‘God Save Qyne [Queen] Elisabeth’ is accompanied by the date ‘1586’ and the initials ‘RP’ and ‘MP’, which probably refer to its original owners. Verzelini managed to retain a ban on imports of foreign glass, which might complete with his now local product.
There are records showing that he did take action when necessary to protect his patent. When he died in 1606 aged 84 he was buried at Downes Church in Kent. There are only 10 existing glasses attributed to Verzelini bearing dates between 1577 and 1590.
Verzelini did not create an industry in England; this feat was finally performed by Sir Robert Mansell. He gained control of the English glass monopoly in 1618 re-organizing the industry on a rational basis.
Mansell was a great entrepreneur. He brought prices down, welcomed new ideas and processes, including the making of mirror plates and wine bottles.
In 1625, when he was encouraging coal-mining to provide his industry with a new type of fuel, he is recorded as having more than 4000 workers under his authority.
King Charles I demanded £1,500 a year from Mansell and his associates, which was paid until the King’s execution in 1649 when all monopolies ended with the advent of Oliver Cromwell’s Commonwealth (1651-1660), the high-water mark of Puritan influence in England.
Glass workers were forced to retreat as their product was seemingly so luxurious…
Though many now are much in debt,
And many shops are to be let,
A golden time is drawing near,
Men shops shall take to hold their ware;
And then all our trade shall flourishing be made,
To which ere long we shall attain;
For still I can tell all things will be well
When the King comes home in peace again.
With the restoration of Charles 11 to the English throne in 1660 the social climate would, encouraged by the court, its style and emphasis on fashion and novelty, change. Opportunities to re-build the economy and run down industries abounded.
Patents for glass making again became available, the first was obtained by the dashing Duke of Buckingham in 1662 who set up a glasshouse at Vauxhall, managed for him by Englishman John Bellingham.
The Royal Society was founded in 1662 to promote scientific research and enquiry…and this was going to augur well for the future of England, the monarchy and the glass industry.
London glass seller of the time John Greene whose invoices cover the period 1669 – 1675 continued to supply Venice glass but in a letter of 3 May 1671 Greene writes to Alessio Morelli, his supplier in Venice….
Sir, I pray you once again to take such care that I may have good, and be used very kindly in the price, else it will not be in my interest to send to Venice for neither drinking glasses nor looking glasses, for we make now very good drinking glasses in England and better looking glasses than any that comes from Venice. ….
Carolyn McDowall, The Culture Concept, October 2011-2013