Origin of The Family Name Jordan

Life in general is full of surprises and genealogical research is no exception. As far as I was concerned, we have always been the Jordan's of Irish ancestry. You can imagine my surprise when I discovered that there is a Jordan Foundation and more so when I established that it was not always Jordan but originally Deardon.
The origin of the name Jordan as confirmed by THE JORDAN FAMILY FOUNDATION is as follows:
“Sir William Deardon, an English knight crusader in the 12th Century who, observed by King Richard the Lion-Hearted to best a Saracen in battle after being knocked off his horse, was dubbed by the king, “Sir Jordan”, after the Jordan River. Sir William subsequently requested it as a permanent name for himself, his descendants, and his home in England
For as far back as I have been able to trace and recall there is a proliferation of “Jack” as a nickname for the males baptised or christened “John”, myself included in the family. At one stage there was in the immediate family, Grandpa Jack, Big Jackie (me) and baby Jackie (nephew). I found this intriguing and asked my father (Grandpa Jack) the reason. He told me that that it was not only a family tradition but occurred worldwide, the reason being that the early Christian churches did not recognise “Jack” as a Christian name and would not baptise a child with that name. Consequently, certainly in our family, a child would be baptised with the good, solid Christian name, “John”. But upon leaving the church the child became Jack or Jackie and remained so for the rest of his life. Legally on paper John but known as and called Jack. You will often see references behind a name AKA (also known as) – In my case John Daniel Jordan, AKA Jack