Thank you Franciscus Cupani.

This is an old variety of Sweet Pea (Lathyrus odoratus) known as Matucana.
The variety was first introduced into Britain in the 17th century by the Sicilian monk, Franciscus Cupani. It has the most wondrous fragrance and produces masses of crimson and violet blooms throughout the summer. Last November it was still bravely flowering away at our back door as the first winter snows arrived.