does it have very sharp thorns? my first thought is blackthorn Prunus spinosa. It certainly looks as if it is in the Prunus genus.

Or possibly Chaenomales (Japanese quince)?

I thought Chaenomeles too -couldn't see any spines, and our blackthorn flowers grow in clusters of smaller flowers.(And the spines are very noticeable and very prickly)When do you cut it? If its is a Chaenomeles it could well develop quince type fruits later in the season.