The Archbishop of Canterbury Justin Welby has unexpectedly been left millions of pounds in his mother's will.

The Most Rev Welby, one of the most senior figures in the Church of England, has been given the fortune following the passing of his mother, Jane Williams – also known as Lady Williams of Elvel – at the age of 93 in July last year.

Leaving everything to her only child, the Archbishop will receive £2,426,242.97 from his mum’s estate according to newly-published probate documents.

However, it is thought inheritance tax could knock more than £800,000 off the total – still leaving Welby with a sizeable £1.5 million.

The cash represents a huge windfall for the Archbishop, who currently makes £85,000 a year in his role as head of the Anglican church.

The Archbishop previously spoke of the pride he felt towards his mother, who beat alcoholism in her younger years and had been in recovery since 1968.

Her death leaves the Archbishop without any parents, with the man Welby grew up believing to be his father – whisky salesman Gavin Welby – dying in 1977 “as a result of the alcohol and smoking”.

It emerged in 2016 that Gavin Welby was not the Archbishop’s biological father, who was in fact revealed to be the illegitimate son of Sir Anthony Montague Browne, the last private secretary of Winston Churchill.

The Archbishop is said to have taken a DNA test after being approached by the family of Sir Anthony.

It is believed he was the product of a liaison between his mother and Sir Anthony just a day or so before her wedding to Gavin Welby.

A statement released by the Archbishop at the time said: "I have discovered that my biological father is not Gavin Welby but, in fact, the late Sir Anthony Montague Browne.

"This comes as a complete surprise.

"My own experience is typical of many people. To find that one's father is other than imagined is not unusual.

"To be the child of families with great difficulties in relationships, with substance abuse or other matters, is far too normal.”