His birth:

Surname First name(s) District Vol Page
Births Mar 1882   (>99%)
Coldham Philip John Docking 4b 329   
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His baptism transcription

First name(s) Philip John Hamilton
Last name Coldham
Sex Male
Birth year -
Baptism year 1882
Baptism date 11 Jan 1882
Father's first name(s) James Henry
Mother's first name(s) Agatha Geraldine
Parish Anmer
Diocese Norwich
County Norfolk
Country England
Archive Norfolk Record Office
Archive reference PD 498/22
Page 45
Record set Norfolk Baptisms
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In 1901 he was with his widowed mother and all of his surviving siblings.

Around 1899 to 1902 he was a Lieutenant with the 3 Volunteer Battalion, The bedfordshire Regiment and is reported to have served in the Boer Wars.

In 1921 and 1954 he was a passenger on a boat from UK toi Mombasa, Kenya.  In 1921 and 1954 he said he was a planter.

Presumably he died in Kenya.  No death or probate record found in UK.
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In 1961 his sister had a Richard John Coldham, medical student, as her executor.  This led to finding this richard as a schoolboy on a boat leaving London in 1947 for Mombasa, Kenya and with an age of 8, giving his birth around 1939.  It is very tempting to deduce that this Richard was the son of Philip John Hamilton Coldham.
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This then led to finding a Coldham website with lists of the various members of the wider family.  This showed that Philip John was the progenitor of an extensive family in Kenya and wider places and the following gives all of this entry for his family including his parents and siblings:

Coldhams on <http://coldham.net>; website

11 Henry James Coldham b: 9 Dec 1839 Anmer, Docking RD d: 1887 Anmer
......+Agatha Geraldine de Courcy Hamilton b: 1850 m: 10 Aug 1870 d: 1932 Bosham, Sussex, testate
...........12 James Henry Hamilton Coldham b: 2 Oct 1873 Anmer d: 7 Mar 1898 Anmer : sold Anmer in 1895
...........12 Alice M. Coldham b: 1874 d: 1968 Snettisham
...........12 Rhoda Geraldine Coldham b: 4 Oct 1875 Docking RD
.................+Rev Oliver Lyne Fowke b: Preston, Rutland d: 9 Mar 1929
...........12 Agatha Maria Coldham b: 28 Jun 1877 Anmer, Docking RD d: 8 Aug 1961 Bosham, Sussex
...........12 Frances Elizabeth Coldham b: 1 Oct 1877
...........12 Philip John Hamilton Coldham b: 19 Nov 1881 Anmer but of Kiambu, Kenya d: 10 Jan 1965
.................+Mary Ellen Seccombe b: Abt. 1880 m: 1 Aug 1910
.......................13 Henry John Seccombe Coldham b: 28 Jul 1911 : MRCS etc.
.............................+Joyce Mary Powell b: Chelsea m: 17 May 1938 Chichester RD
...................................14 Richard John Coldham b: 24 Nov 1938 of Lusaka, Zambia
.........................................+Muriel Frances Brierley b: Wellington, New Zealand m: Lusaka
...................................14 Rosemary Anne Coldham b: 11 Jan 1940
.........................................+Basil Walter Osborne b: Australia m: 1964 Australia
...................................14 Peter James Coldham b: 2 Oct 1946
...................................14 Sarah Elizabeth Coldham b: 6 Nov 1948 Kenya
.......................13 Charles Hamilton Coldham b: 18 Aug 1914 : Commander R.N., of Nairobi, Kenya
.............................+Agnes Hetherington b: Glasgow m: 1942
...................................14 Denise Marilyn Coldham b: 15 Apr 1945 of Bognor Regis
...................................14 Charles Nicholas Seccombe Coldham b: 3 Oct 1949
.......................13 Elizabeth Mary Coldham b: 24 Dec 1915
.............................+Harry Ramsbottom m: 14 Aug 1948
...........12 Lucy Maud Coldham b: 4 Feb 1884 d: 12 Jul 1970
.................+George Lewis Langridge b: Kenya m: 1908 d: 2 Jan 1958

Unfortunately there is no easy access to Kenyan records to confirm all this and Peter Wilson Coldham, who compiled this genealogy, is alas no more, having died in 2012.

It showns that Richard John Coldham was in fact the grandson of Philip John Hamilton Coldham.
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