Where did the guitar originate?

Stringed instruments similar to the guitar have existed for a very long time and developed more than one time in different places. Stringed instruments existed even in Ancient Egypt and Ancient Rome. They also existed in Medieval Europe, but at that time in Europe another stringed instrument, the lute, was more popular. For most of its history, a guitar wasn't clearly defined. For example, guitar-like instruments had different numbers of strings made out of different materials. The modern guitar is very similar to a vihuela, a 17th century Spanish instrument that had 6 strings made of guts. Also, music written for the vihuela was written in pretty much the same way that music for the modern guitar is written. Still, the origin of the guitar is controversial. For example, some argue that the guitar originated in Italy rather than Spain.