The hawthorn tree growing in the garden is, as far as I can tell, a hybrid called “Paul’s Scarlet”.
It is a hybrid of woodland hawthorn, Crataegus laevigata and common hawthorn, Crataegus monogyna. It produces deep pink double flowered blossoms that look rather stunning.
I must admit though, that I prefer the simple pale pink/white blossoms of the common hawthorn that you find growing wild in hedgerows. These flowers also provide food for hazel dormice, as well as being important to a huge variety of insects and birds. You can read about it in my previous post, Hawthorn Blossom.