His life was the subject of a cycle of frescos by Antonio Veneziano in the Campo Santo.
According to later stories, he was canonised by Pope Alexander III.
In 1161 or 1162 a Pisan canon named Benincasa wrote a long and invaluable vita of the saint.
He says Rainerius resembled the son of God through his life of strict imitatio Christi (imitation of Christ).
Benincasa also goes so far as to claim "a royal priesthood in Christ" of which Rainerius and all the baptised were a part.

With the growth of Pisan influence, Rainerius's cult spread throughout the Mediterranean.
In 1632 the Archbishop of Pisa, the local clergy, and the Pisan magistrates elected Rainerius as the patron saint of the city and the diocese.
In 1689 his body was translated to the altar of the Duomo.
He is generally portrayed as a bearded hermit in a hairshirt holding a rosary; as a young pilgrim in a hairshirt carrying a banner with the Pisan cross; as being raised up by devils; or as dying in a hairshirt.
His life was the subject of a cycle of frescos by Antonio Veneziano in the Campo Santo. According to later stories, he was canonised by Pope Alexander III. In 1161 or 1162 a Pisan canon named Benincasa wrote a long and invaluable vita of the saint. He says Rainerius resembled the son of God through his life of strict imitatio Christi (imitation of Christ). Benincasa also goes so far as to claim "a royal priesthood in Christ" of which Rainerius and all the baptised were a part. 
With the growth of Pisan influence, Rainerius's cult spread throughout the Mediterranean. In 1632 the Archbishop of Pisa, the local clergy, and the Pisan magistrates elected Rainerius as the patron saint of the city and the diocese. In 1689 his body was translated to the altar of the Duomo. He is generally portrayed as a bearded hermit in a hairshirt holding a rosary; as a young pilgrim in a hairshirt carrying a banner with the Pisan cross; as being raised up by devils; or as dying in a hairshirt.
Rainerius