The original ukuleles were a combination of several instruments from the Iberian Peninsula of Europe brought to Hawaii along with sailors and plantation workers in the 1880s. The ukulele combined elements from the Cavaquinho from Portugal and the Braguinha and Rajão from Maderia near the Canary Islands.
The Cavaquinho looks like a little guitar with four strings. The Portuguese sailors brought their cavaquinhos on their travels in the 15th and 16th centuries, spreading the instrument to other cultures, influencing the Maderia Braguinha, Brazilian Cavaquinho, and the ukulele in Hawaii. The Rajão, also from Madeira, has 5 strings and its D-G-C-E-A tuning is thought to be the root of modern ukulele tuning. Today's Hawaiian soprano ukulele has 4 strings, just like the Braguinha, but is tuned G-C-E-A just like the Rajão.