The earliest written evidence of Maltese is a ballad by Pietro Caxaro, (d.1485). The Knights attempted to script it as well. The survival of the language is perhaps testament to the resilience of the Maltese to remain a distinct people and culture. Malti is thought to derive from the language of the ancient Phoenicians who arrived in Malta in 750 B.C.
And more https://en.wikipedia.org/wiki/Maltese_language