Simplify the following text for a Grade 7 native English-speaking person.
Original: In the 13th century St. Francis of Assisi established the Franciscans , or so-called `` Grey Friars '' , a mendicant order .
Simplified: In the 13th century St. Francis of Assisi started the Franciscans , who were often called the `` Grey Friars '' because of their grey-brown robes .