Much of the following comes from research done by John Martin (indicated in text) - I have added to it where I can. As the principal males are nearly all called William, I have numbered them.
William (1) born 1803
William (2) bapt. 1835
William (3) born 1868
William (4) born 1889
In 1803, at 3,Tavistock Cottages, Roborough, Plymouth, Devon a child was born to Richard and Maria Martin (source: John Martin). The Batter Street Presbyterian Plymouth records show a William Martin (1), son of Richard and Maria, being born on the 24th March of that year, and baptised on 29th April (www.familysearch.org)
At least 3 children were born before William, on an almost yearly basis, and at least 3 were born after him: Maria (1799), Richard (1800), Elizabeth (1802), Mary Ann (1804), Jane (1806) and Harriett (1808) (www.familysearch.org)
A Martin family later living in the Charles the Martyr parish may be a different Richard and Maria.
Robert, the son of Richd and Maria Martin, was baptised in January 1815, in St Andrew parish. Richard was a farmer.
Bishops Transcripts St Andrew, Plymouth
Julia Martin was baptised in November 1822, the daughter of Richard and Maria, of Tavistock Road. Richard was a farmer.
Parish records, Charles the Martyr, Plymouth
At the time of the 1841 census, a Richard and Maria Martin are living Tavistock Road, Charles the Martyr sub district, Plymouth, with a number of younger Martins who may or may not be their children (the 1841 census does not specify relationships). Richard and Maria are both circa 60 (the census also rounds down ages); Maria is 35, Sarah and Robert are both circa 25, Jane Ann and Julia are both circa 20. All were born in Devon.
Maria Martin, aged 73, was buried in the parish of Charles the Martyr in May 1850. She was 73, and her abode had been Tavistock Street.
Parish records Charles the Martyr, Plymouth
1841 census HO107, Piece 271, Civil Parish Charles The Martyr, County Devon, Enumeration District 2, Folio 5, p5
1851 census HO107. Piece 1878, Folio 550, p29
By 1861 Richard, now 84, was a proprietor of houses, living at 27 Tavistock Road. His unmarried daughter Jane A Martin is with him on the census.
1861 census RG09, piece no. 1438, folio 60, p1
Richard Martin, aged 90 and of Portland House, died on May 25th 1867 (Vicar's note). He was buried in the parish of Charles.
Parish records, Charles the Martyr, Plymouth
None of the above details match the earlier baptismal records quoted above, and family tradition has it that both Richard and Maria had died by the time of the 1841 census. Believed to have been originally from France, the story goes that both were returned there for burial (source: John Martin).
By 1835 William (1) may have been in Ashburton, married to Elizabeth. On 7th January a William Martin was baptized to William and Elizabeth, but the father is said to be a butcher. All other references to William (1) describe him as an ag lab (agricultural labourer) or farm labourer.
In 1841 William (1) and Elizabeth are living with 6 year old William (2), Emma and Jane. William is an ag lab (agricultural labourer).
1841 census HO107, Piece 253, Civil Parish Ashburton, County Devon, Enumeration District 10, Folio 13, p20
The 1851 census shows the Ashburton William as a farm labourer, with wife Elizabeth and children Emma, Jane, Eliza and Elizabeth. William says he was born in Plymouth.
Emma, Edith and Sarah are shown with their parents on the 1861 census (http://www.freecen.org.uk/) William (1) is an ag lab and the family live in North Street. Elizabeth (maiden name also Martin) was born in Ashburton, and worked as a laundress.
Elizabeth's maiden name confirmed from the birth references to her children on https://www.gro.gov.uk
Devon Heritage Centre holds a licence for the marriage of William Martin of Ashburton and Elizabeth Martin of Tor Moham. The licence is dated 10th September 1834.
Devon Heritage Centre ref DEX/7/b/1/1834/426
https://devon-cat.swheritage.org.uk/records/DEX/7/b/1/1834/426 - Accessed 11-10-2018
A William Martin married an Elizabeth Martin at Tormoham on Sept 12th 1834 https://familysearch.org
Moving forward to the September quarter of 1863, an Elizabeth Jane Martin Spry was born in the Totnes district of Devon http://www.freebmd.org.uk/, and a William Martin Spry (3) was born in the Newton Abbot district September quarter 1868. There is little doubt that these are the children of William Martin (2) and Sarah J Spry, because they married in the Newton Abbot district during the June quarter 1872*
* And are living as man and wife in Ashburton on the 1871 census http://ancestry.co.uk
On the 1881 census both William (2) and Sarah J are in Cad Lane, Ashburton, with 5 children including Elizabeth Jane and 12 year old William (3). William (2) is a general labourer.
On the night of the 1891 census, http://www.freecen.org.uk/ only William (3) and one of his brothers is with their parents. William (3) is a general labourer, as is his father.
The Martin family are still in Cad Lane, but not too far away at Great Bridge is another family, headed by a widow named Mary J Pascoe. She is a wool weaver from Cornwall, and on census night her unmarried sister, Sarah A Found is staying with her. Mary J has 3 children, two of them born in Yorkshire. But the youngest, William, aged 1, was born in Ashburton.
Looking at the FreeBMD records, William Martin Pascoe (4) was born in the Newton Abbot district during the December quarter of 1889. But William Martin (3) did not marry Mary Jane Pascoe until after the census in 1891 (in the Newton Abbot registration district June quarter 1891 http://www.freebmd.org.uk/)
William Martin (3) is living with his wife Mary J. at Crockaton in the 1901 census. Also in the household are William (4) aged 11, John aged 9, Lily, 5 and James aged 1.
1901 census RG13; Piece: 2053; Folio: 29; p 23
http://interactive.ancestry.co.uk/
William Martin (4) married Beatrice Dorothy Bray on the 4th October 1913 at Devonport. Beatrice Dorothy Bray had been born 25th May 1892 in Buckfast, Devon (source: John Martin).
William Martin (4) had a long and eventful life. He joined the army before World War I, and worked his way up the ranks to warrant officer. He was recommended for the Distinguished Conduct Medal 5 times, and served in many of the major battles of the 1914-18 conflict - the Somme, Hill 60 and Ypres.
Returning to Ashburton, he became a publican, running, with his wife, the Royal Oak, then the London Hotel and finally the Rising Sun at Woodland, where in the 1950s there were only oil lamps to light the bar
The electoral register of 1930 shows William Martin and Beatrice Dorothy Martin at the Royal Oak Inn.
Electoral registers 1920 -1932, availabe through https://www.findmypast.co.uk
William and Beatrice were married for 68 years and had two children - Eileen, and Russell Herbert. William was 92 when he died.
Many thanks to Roy Martin for the above.
Above: William and Beatrice Martin, 1960's.
Thanks to Christine Lunt for this photograph
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Above: Russell Herbert Martin married Rose Byott at Newton Abbot, Devon, 28 August 1946
Thanks to Roy Martin for this photograph
The Pascoe Family
As is shown above, in the 1891 census there was a family at Great Bridge headed by a widow named Mary J Pascoe. She is a wool weaver from Cornwall and she has 3 children, two of them born in Yorkshire. The youngest, William, aged 1, was born in Ashburton (http://www.freecen.org.uk/).
The two elder children are Francis Pascoe, aged 8, and Mary E(lizabeth) Pascoe, aged 6
Mary Elizabeth married a Penwarden (source: Christine Lunt) - probably Herbert J Penwarden, in the Holsworthy district in the September quarter 1911.
Below: Mary Elizabeth Pascoe.
Thanks to Christine Lunt for this photo
Below: believed to be Mary Jane Martin, formerly Pascoe, nee Found, and her mother
Thanks to Christine Lunt for this photo