Short answer: We don’t know – but we can guess!
Long answer...
You might remember hieroglyphs from school. Ancient Egyptians scrawling images on walls and stones that looked something like this:
Photo credit: the British Museum (from the tomb of Pharoah Seti I)
Tell-a-Phoenician
Those symbols are a far cry from the letters on this page, so we have to jump to Phoenicia (about 1550 BCE – 300 BCE). They are credited with the precursor to our alphabet.
Photo credit: Encyclopedia Britannica
Since they came up with the alphabet, it’s tempting to think the name Phoenicia is related to words relating to speech like phonics, phonetic, or phone. Sadly it’s not – Phoenicia likely comes from phoinix, or ‘purple’, which relates to a lucrative purple dye they used to create and export.
The Phoenicians were fantastic traders and wrote down their transactions. The letters were simple to write and easy to learn. Eventually the Phoenician alphabet spread along the trade routes too, especially when people wanted to check what they were receiving.
Would you like to buy a vowel?
The alphabet didn’t have vowels yet. When Phoenicia was conquered by Greece - who in turn fell to Rome - Greece adopted the Phoenician alphabet and added vowels to suit Greek speak.
Let’s track how the alphabet evolved.
Photo credit: Matt Baker at Useful Charts
The Order of the Phoenic’s
So the order of the alphabet has been consistent since the Phoenicians, but why did they put it in that order?
Here are 2 guesses:
1. Letters may have represented numbers – this is known as gematria.
This would mean in English; A would be 1, B would be 2, and so on until J = 10. Then K = 20, L = 30 and so on until you reach 100, 200, etc. So the order of the letters is made to match the order of numbers.
2. It was a mnemonic to help people learn and remember all the letters.
It may be like our modern-day alphabet song or a long sentence using the whole alphabet. Such a mnemonic may be tedious – and by charting dictionaries entirely for great humans, I just know languishing minds notice orderly patterns, quickly recite sentences, then understand variability when x-rays yet zigzag.
Wow that was hard to write.