Oil on canvas, 130cm by 96cm.
Bruno of Cologne was the 12th Century founder of the Carthusians, a monastic order committed to solitary meditation.
The painting was probably acquired by Brownlow, 9th Earl of Exeter (1725-1793) whilst in Rome on the Grand Tour.
It depicts a vision Bruno had of angels appearing in the sky, with allusions to the crucifixion in the crossed trees.
There is another version in the Louvre in Paris.
Mola was born in what is now Switzerland, but spent most of his life in Rome.
Although he painted some highly regarded frescoes, his best work is considered to be his small paintings, particularly of landscapes.
