His commemoration is today.
You can read his story here or here.
Here is one of his best loved prayers:
Canticle of the Sun
Most high, most-powerful, all-good Lord,
All praise is Yours, all glory, honour and blessings.
To you alone, Most High, do they belong;
no mortal lips are worthy to pronounce Your Name.
We praise you, Lord, for all Your creatures,
especially for Brother Sun
who is the day through whom you give us light.
And he is beautiful and radiant with great splendour,
of you most High he bears Your likeness.
We praise You, Lord, for Sister Moon and the stars,
in the heaven You have made them bright, precious and fair.
We praise you, Lord, for Brothers Wind and Air,
fair and stormy, all weathers moods,
by which You cherish all that You have made.
We praise you, Lord, for Sister Water,
so useful, humble, precious and pure.
We praise you, Lord, for Brother Fire,
through whom you light the night.
He is beautiful, playful, robust and strong.
We praise you, Lord, for Sister Earth,
who sustains us with her fruits, coloured flowers and herbs.
We praise you, Lord, for those who pardon,
for love of You bear sickness and trial.
Blessed are those who endure in peace,
by You most High, they will be crowned.
We praise You, Lord, for Sister Death,
from whom no-one living can escape.
Woe to those who die in their sins!
Blessed are those that She finds doing Your will.
No second death can do them harm.
We praise and bless You, Lord, and give You thanks,
and serve You in all humility.
Image: my photo of a statue in precincts of St George's Cathedral, Jerusalem.
Words for Canticle of the Sun: in public domain.