Zero and the Nine Figures
The Islamic Golden AgeZero Was Not Invented in Baghdad
Zero was not invented in Baghdad. It arrived there. Babylonian scribes had used a placeholder mark centuries earlier, but as a gap-filler inside a numeral rather than a number you could operate on. In 628 the Indian astronomer Brahmagupta finished the Brahmasphutasiddhanta and set out arithmetic rules for zero itself: what happens when you add it, subtract it, multiply by it. The oldest surviving dated zeros are cut in stone. Two inscriptions carry the year 605 in the Indian Saka era, which is 683 CE — one from Sambor in Cambodia, one from Kedukan Bukit in Sumatra — both using a dot where we would write 0. The oldest known in India itself is an inscription at Gwalior, dated 876, where a temple record has the figure 270 on its wall — though the Bakhshali manuscript, which uses a dot for zero throughout, may be older still: the Bodleian's radiocarbon tests spread its folios across the ninth to twelfth centuries, so it cannot settle the question.
A Story with No Eyewitness
How the system reached Baghdad is itself a lesson in thin evidence. Around 773, the story goes, an Indian visitor brought an astronomical work — the Sindhind — to the court of the caliph al-Mansur, and al-Fazari turned it into Arabic. That account reaches us from Ibn al-Adami, writing around 925, and survives mainly because al-Qifti copied it down in the thirteenth century. No eyewitness, in other words. What is firmer is what followed: around 825 al-Khwarizmi wrote a manual on calculating with the Indian figures, and around 830 al-Kindi produced a four-volume treatise on the same subject. Neither claimed the figures as his own invention. Both called them Indian.
Nine Figures, and the Missing Tenth
The words came with the digits. Sanskrit shunya, meaning empty, became Arabic sifr; Latin took that as zephirum and cifra, and English pulled both zero and cipher out of the same root. The figures themselves travelled in two shapes: the eastern forms still written from Egypt to Iran, and the western Maghrebi ghubar or dust forms, which are the direct ancestors of the 1, 2, 3 you are reading. Those reached Latin Europe early. The Codex Vigilanus, copied at the monastery of Albelda in the Rioja in 976, shows nine of them. Nine, not ten — no zero. Gerbert of Aurillac, later Pope Sylvester II, put the same nine on abacus counters in the 980s, again without zero, and without a zero you cannot hold an empty column open. That is the whole trick.
The Customs House at Bugia
Guglielmo Bonacci was a Pisan notary posted to the customs house at Bugia — modern Béjaïa, on the Algerian coast — handling the affairs of Pisa's merchants. He sent for his son. In the prologue to the Liber Abaci, finished in 1202 and revised in 1228, that son describes being introduced to "the art of the nine Indian figures" at the school of accounting there, and liking it above everything else. The book's first chapter lists the figures from 9 down to 1, then the sign 0, which he notes the Arabs call zephirum. He signed himself Leonardo Pisano; the name Fibonacci was popularised by a historian only in the nineteenth century. His way in was the counting-house rather than the library, which is why the Liber Abaci is thick with prices, weights and currency conversions. But it is not merchant arithmetic alone: the prologue goes on to describe further study in Egypt, Syria, Greece, Sicily and Provence, and the book's algebra follows the tenth-century Egyptian mathematician Abu Kamil closely.
The Ban That Never Happened
You have probably heard that medieval Europe banned these digits as devil's work. It did not happen. The historian C. Philipp E. Nothaft traced that claim in 2020 and found it unsupported at nearly every level — a modern invention, not a medieval fear. The real episode is smaller and more interesting: in 1299 Florence's money-changers' guild told its members to write sums in words or Roman numerals in their books. The worry was forgery rather than religion: the new figures are easy to alter, and historians point out how little it takes to turn a 0 into a 6 or a 9. What followed was not a ban but a slow, uneven changeover — abbaco schools spreading out of northern Italy, then printing — with Roman numerals still doing real work in account books into the sixteenth century.
Key Dates to Remember
- 628 — Brahmagupta completes the Brahmasphutasiddhanta in India, giving arithmetic rules for zero as a number rather than a blank space.
- c. 825 — Al-Khwarizmi writes his manual on calculating with the Indian figures in Baghdad; the Arabic original is lost, and only Latin adaptations survive.
- 976 — The Codex Vigilanus, copied at the monastery of Albelda in the Rioja, shows nine of the figures in a Latin manuscript — with no zero among them.
- 1202 — Leonardo Pisano finishes the Liber Abaci, crediting the accounting school at the Bugia customs house where he learned the nine figures.
- 1299 — Florence's money-changers' guild requires ledger sums in words or Roman numerals, on grounds of forgery rather than religion.