It was an 'independent', quite serious Orthodox Church, 'vagante' as others would call it.
It had its origins in 1866 in the consecration of a French man - Jules Ferrette - by the Syrian Orthodox as a bishop for the West with a view not to introducing Syrian Orthodoxy but rather restoring the Orthodox Church to the West and thereby being a focus for Church reconciliation and unity.
Of course the Anglicans were having none of that! And threatened any priests who had anything to do with him with discipline. He did gather some followers though - especially since ecumenism based on historic Apostolic Christianity was in the air.
Anyhow, cut the story short. Small church. Many years of struggling on. Abandoned by Mother Church. Present bishop a very sound man. Relationship develops with Copts. Union with Coptic Orthodox Patriarchate achieved.
In fact 25 years earlier the Copts had already united a French 'vagante' group with the Patriarchate and this is flourishing in France as a French language Orthodox mission to French people. So the Copts had a history of imaginative acts of pastoral and missionary endeavor.
My bishop and other members of the BOC have just returned from a pilgrimage to Egypt, where, as ever, they were welcomed as completely members of the COP. Indeed my own priest was in tears remembering how moving the trip was for him.
I first met this group about 14 years ago and was impressed by their seriousness and the lack of cult-like attributes. They were open and friendly and never tried to convert me in a negative sense, and they were always aware that they needed to be in a relationship with wider Orthodoxy. In fact my own bishop wrote publically that he would be willing to give up his episcopate if it was necessary to bring about that reunion which was required for the spiritual wellbeing of the people in his care. When I read that I knew he was not like many other bishops - in name only - who care for no-one and heap up empty titles.
As far as I can say joining the COP was the best thing possible and has been a treasure house of blessings from the beginning.