William Joseph was the eldest son of William Montague and Kitty Glenister. 

William Joseph was the first of the eight sons and two daughters of William Glenister, Chief Constable of Hastings, he is buried in the graveyard at Fairlight Church near Hastings with his wife Emma.
They are buried to the immediate right of their son Wilfred Montague Glenister

The inscription on their grave reads:-

In loving memory of my dear husband
William Joseph Glenister, born 21st July 1850, died 20th October 1929.
Here rests also our dear mother Emma Elizabeth Glenister, the beloved wife of the above, born 18th September 1851, died 28th June 1934.
In grateful remembrance of our beloved parents.

William was born in St Johns Wood, Middlesex and moved to Hastings with his father, In 1881 William lived at 199 St Georges Road, and was a Solicitor.
By 1899 Kelly's Directory of Sussex has his address as 27 Pevensey Road and he is still recorded as living there in 1915.
In 1899 he is recorded as being Deputy Coroner at 8 Bank Buildings, the address of Jones (Davenport) & Glenister, Solicitors but the directory seems to be having name problems, recording him as William James in this entry and as Glennister at his Pevensey Road address!
Connection with the fire brigade is retained by William, he was Hon. Treasurer, his brother Louis Oliver was at that time 2nd officer at No 1 District in the Old Town.
By 1915 his second son, Harold William Glenister OBE is recorded as living at 27 Pevensey road as well, also a Solicitor working at 8 Bank Buildings with Jones (Davenport) & Glenister. and William was now the Coroner for Hastings.

It is possible that William may have had a twin sister, Emily, but there is no record of her birth or reference to her in the will of William Montague, Emily is found in the 1851 census and possibly married ??Akehurst.  There is a record of Elizabeth Akehurst, possibly her daughter living with Charles Laurence Glenister in 1891, apart from that nothing is known.

William's family tree         1881 census