The guitar was first known as an instrument called the vihuela in Spain around the turn of the 15th century. It originally had four double-strings (eight strings in total) and evolved from earlier stringed instruments similar to lutes and ancient plucked instruments possibly dating back thousands of years including ones from ancient Egypt and Mesopotamia. The modern six-string guitar, closer to what is known today, became popular in Europe in the 1800s, with significant design advancements made by Spanish guitar maker Antonio de Torres in the 19th century who developed the shape and size of the modern guitar. In summary, the guitar as we know it originated in Spain around the 15th century, evolving from earlier string instruments and reaching its modern form by the 19th century through technological and design improvements.