It has been reported that Lord Snowden died in his sleep aged 86. His son, with Princess Margaret, David Armstrong-Jones, Viscount Linley, becomes the 2nd Earl of Snowdon.
Here is some biographical info on him related to royal history.
Antony Charles Robert Armstrong-Jones, 1st Earl of Snowdon, GCVO, RDI (7 March 1930 – 13 January 2017), commonly known as Lord Snowdon, was an English photographer and film maker. He was married to Princess Margaret, younger daughter of King George VI and younger sister of Queen Elizabeth II.
In February 1960, Snowdon, then known as Antony Armstrong-Jones, became engaged to the Queen’s sister, Princess Margaret, and they married on 6 May 1960 at Westminster Abbey. The couple made their home in apartments at Kensington Palace. As he was a commoner, he was created Earl of Snowdon and Viscount Linley, of Nymans in the County of Sussex on 6 October 1961 due to concerns over the prospect of a British princess giving birth to a child without a title. The Snowdon title has centuries-old royal associations, since the name Snowdon was borne by the Welsh princes and the House of Gwynedd before 1282, though here it was granted as a nod to Armstrong-Jones’s Welsh ancestry. A Barony of Snowdon (sometimes spelled Snaudon) was a subsidiary title of King George II’s son Frederick, Prince of Wales. The subsidiary Linley title honoured Lord Snowdon’s great-grandfather Linley Sambourne as well as Nymans, the Messel family estate in West Sussex.
The couple had two children: David Armstrong-Jones, Viscount Linley, born 3 November 1961, and Lady Sarah Armstrong-Jones, born 1 May 1964.
The marriage began to collapse early and publicly.
On 16 November 1999 Lord Snowdon was created Baron Armstrong-Jones, of Nymans in the County of West Sussex This was a life peerage given him so that he could keep his seat in the House of Lords after the hereditary peers had been excluded. An offer of a life peerage was made to all hereditary peers of the first creation (those for whom a peerage was originally created, as opposed to those who inherited a peerage from an ancestor) at that time.
The government of the day had expected Lord Snowdon to follow the example of members of the royal family and turn down his right to a life peerage. At the time, Labour MP Fraser Kemp said he was “shocked and surprised that someone who achieved their position in the House of Lords by virtue of marriage should accept a seat in the reformed Lords”.
He retired from the House of Lords on 31 March 2016.