Ladino
Ladino, also called Sephardic, is a Romance language, originating among jewish people, living in moorish Spain.
History
It diverged from the Spanish language the same way the Yiddish language diverged from the German language. Jewish people lived relatively isolated from their neighbors, isolated enough for the languages to diverge.
The moors had conquered Spain by the early eighth centuries. Charles Martel stopped Muslim expansion into what is now France at the Battle or Tours, in 713. During the next 700 years small Christian kingdoms very slowly conquered bits of moorish Spain.
Spain's muslim rulers had been relatively tolerant of jewish people. The new Christian rulers weren't tolerant of either muslims or jews. The Spanish inquisition put great pressure on muslims and jews to either convert to Christianity, or pretend to convert to Christianity, while practicing their real religion in secret, or to leave. Jewish people fleeing the Spanish inquisition spread Ladino across North Africa.