In 1213, King John, of England (not yet the United Kingdom) dispatched the country’s first embassy to Morocco. The aim of that first diplomatic mission was to make contact with the court of Morocco’s Sultan Mohamed Ennassir – the fourth Sultan in the Almohad dynasty. King John hoped he could secure the Almohads’ support in England’s conflicts with European enemies.
It is reported that King John asked for an alliance against France and support against his enemies within England with the promise that he would embrace Islam. The details of this embassy, according to P. G. Rogers, A History of Anglo-Moroccan Relations to 1900, pp.1-5, were recorded by Mathew Paris and later published and kept at Saint Alban Abbey.
The UK government website celebrates 800 years of relations – https://www.gov.uk/government/world-location-news/800th-anniversary-of-uk-morocco-relations