Quaternion
 

The quaternion number system extends the complex numbers.
Quaternions were first described by Irish mathematician
William Rowan Hamilton in 1843[1][2]
and applied to mechanics in three-dimensional space.

Hamilton defined a quaternion as the quotient of two directed lines
in a three-dimensional space,[3] or equivalently,
as the quotient of two vectors.[4]
Multiplication of quaternions is noncommutative.

In modern mathematical language,
quaternions form a four-dimensional associative normed division algebra
over the real numbers, and therefore also a domain.

Wiki

The concept of quaterinions was realized by the Irish mathematician Sir William Rowan Hamilton
on Monday October 16th 1843 in Dublin, Ireland.
Hamilton was on his way to the Royal Irish Academy with his wife and as he was passing over
the Royal Canal on the Brougham Bridge he made a dramatic realization that
he immediately carved into the stone of the bridge.

i^2 = j^2 = k^2 = ijk = -1

https://www.3dgep.com/understanding-quaternions/