Before knowing about history of integers we must first know what integers are. IntegerNumbers are the numbers which include negative numbers, zero and positive numbers, but integers don’t include fractional and decimal numbers. The example of Integer numbers is shown below-
-9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
The numbers shown above are integers, in this example numbers start from negative number -9 and go to positive number 9 and also include 0.
Now let us discuss History of integers, integers are one of the very important units of mathematics from centuries, integers have contributed a lot in development of concepts in mathematics. People think that integers were one of the first numeric systems developed for counting but it’s not true, our ancestors used their fingers or objects like stones for counting.
The history of integer’s dates back to Babylonian times which is about 4000 year old, after Babylonians, Greeks again made some changes in the system of Algebra and integers given by Babylonians.  “Diophantus of Alexandria”, Greece gave the concept of solving system or Set of equations using integers in year 250 A.D. This concept was applicable for finding solutions for both single equation and set of equations involving one or more than one unknown variables but the result obtained was always in the form of whole numbers.
Then Europeans made new breakthroughs in field of mathematics using integers. Mathematician Carl Friedrich Gauss gave some new concepts about integers in his book Arithmetical Disquisitions in year 1795. Then later Great Albert Einstein showed the importance of Gauss’s theory and used this concept in development of theory of relativity. Later mathematician “Leopold Kronecker” gave some concepts about integers which were improvement over above previous theories about integers.
This is all about history of integers.