It's almost hard to believe that the common graphite pencil was once very uncommon. In the 1500's a large graphite deposit was found in England. Up until then metal, sometimes lead, stylus' were used to write with. At the time artists had a number of drawing medium's to work with from charcoal, different color chalks, silverpoint and ink, but not graphite.
That large deposit of Graphite was horded by the English Crown because graphite was used to line the molds that make cannonballs. Although the deposit of graphite was guarded some was smuggled out and used by the people in that region. Latter, methods were devised for mixing the graphite with clay to harden it. It was then encased in wood and the modern pencil was born.
The pencil took sometime to catch on as an artist medium . It is in the 18th and 19th centuries that you begin to see it more widely used. Now, pencil drawings are so common and there is a wider variety of pencils to be had. There are pencils with a variation of hard or soft graphite, color pencils, wash pencils, watercolor pencils, mechanical pencils and pencils that emulate ink.
The pencil is probably the first medium used by every budding artist and the one we always return to.