The Goths were one of the most important "barbarian" tribes responsible for the downfall of the Roman Empire and the politics of early Medieval Europe. By the 4th century CE, the Goths were becoming Christianized. At this time, the Goths wrote their language using their version of the Futhark alphabet, but it was deemed to be a pagan invention. Instead, Bishop Wulfila (or Ulfilas), a Greek missionary responsible for the conversion of the Goths to Christianity, took the Greek alphabet, added letters from Latin and Futhark alphabets, and created a new alphabet to write the Gothic language.
Note that there are two letters that don't stand for any sounds. This is because they were adopted from Greek only for their numeric value. The Classical Greek alphabet doubled as a number system, and each letter had a number associated with it. The Gothic alphabet continued this tradition, and so in the case of Gothic, the first row of letters have numeric values of 1 to 9, the second row from 10 to 90, and the third row from 100 to 900.
The Goths spoke a Germanic language, and it is unique not only in that it is the earliest documented Germanic language, but also in that it is the only language in a completely separate branch of the Germanic family unrelated to any other surviving Germanic languages.
In most of Europe, the Gothic alphabet and language slowly faded into obscurity by the 9th century CE. The Gothic language survived in the Crimea but it too became extinct around the 17th century CE.