History is a collection of stories. To understand how these stories connect, we need to arrange them in the order they happened. The tool we use for this is called a timeline. Think of it like a ruler for time, where events are marked down instead of centimetres.

Just like a ruler has a starting point, a historical timeline needs an anchor. For the calendar system used most widely today, this anchor is a single moment: the start of Year 1. Everything that happened before this point is in one category, and everything after is in another. It splits all of history into two distinct eras.

Here is a curious fact: there is no Year Zero. The timeline jumps directly from the year before the anchor to Year 1 itself. It goes from year '1 Before' straight to year '1 After', with no stop in between. This detail is important for understanding how historical dates are counted.

The easiest way to picture this is with a number line. You might remember this from maths class. Zero is in the middle, with positive numbers stretching to the right and negative numbers stretching to the left. A historical timeline works in a very similar way, but with Year 1 as the central point of division.

This straight-line approach is called a linear perspective of time It treats time as something that moves forward continuously without repeating. One event follows another in a sequence. While this seems obvious to many of us today, it's not the only way people have thought about time. Some cultures viewed time as cyclical, like the repeating seasons of the year.

For studying history in a global context, the linear model is incredibly useful. It gives us a shared framework to place any event, from the building of the pyramids to the invention of the internet, into a logical order. This simple line, anchored at Year 1, is the foundation for all the history we will explore.