Gosh, this man is difficult to trace! I'd be interested to hear what the Green Room Club have got on him, and whether anything below is correct at all. He's not immediately obvious in any genealogical records, so I thought I'd do a bit of detective work.
I've come to the conclusion that either the "John Powles" bit was his stage name, or he was adopted.
Looking at the address on the MIC - Miss M.A.Wickens (aunt), 2 Talbot Sq, Sussex Gdns - there is indeed a Minnie WICKENS living at this address on the 1911 Census. She's the 59yo cook to two elderly spinsters, Mary and Katharine BRUCE.
Her age and birthplace (Rotherfield, Sussex), make it fairly certain that she is one of the two Mary Ann WICKENSes born in Uckfield district in Q4 1852 (no Minnies/Wilhelminas born there at the time).
One of these Mary Ann WICKENSes (daughter of William and Susannah, living in Wadhurst by 1861) had a sister Louisa, born Rotherfield Q2 1854), who married James CURTIS (from Necton, Norfolk) in Wandsworth district in Q4 1872.
On the 1881 census, these two have a "son" Arthur, age 1, born Battersea, but I can't find an Arthur CURTIS born in Wandsworth/Battersea in 1879-80.
If he was born plain Arthur CURTIS, then his birth registration might be Lewisham Q3 1879. He's definitely not Woolwich Q1 1880, as this is a different family.
James, Louisa and Arthur are living at 49 Russell St, Battersea, in 1881. James is a bricklayer.
James and Louisa can be tracked through 1891 (still in Russell St), 1901 (at 37 Gladstone Terrace, Battersea) and 1911 (at 32 Brougham St, Battersea), but Arthur isn't with them.
In 1891 he may be the 11yo Arthur CURTIS, scholar at "Catholic Schools, Union Street, South Mimms, Barnet" (St Andrew's boarding school?). But his place of birth is given as "London", so it could easily be someone else.
Given his acting career, in 1901 he is almost certainly the Arthur CURTIS, 21, Actor, born "Islington", boarding with Mary Ann AUSTIN and her daughter Mary at 83 Loughborough Rd, Lambeth.
I can't readily find Arthur in 1911. But the entry for his parents is intriguing:
James CURTIS, Bricklayer, born Necton, age sixty-something overwritten 44 (his DoB varies with each census, but he must be 67-ish by now), wife Louisa, born Wadhurst, Sussex, age 57, married 30 years. [So it's definitely the same couple.]
Children born to this marriage: None !
Does this mean that the CURTISes adopted him? Was his name before adoption Arthur POWLES or Arthur John POWLES? I can't find any likely birth registration under any combination.
I think Louisa died in Wandsworth district in Q4 1914, and James is probably one of the several deaths in London between 1911 and 1917 of a James Curtis born between 1843 and 1846, but it's impossible to say which because we never know his true age.
So his aunt Minnie was his closest living relative after the war.
It's all rather confusing really!

Hope the Club can fill in some of the blanks.
Adrian