Shaun:
Welcome to Ireland Reaching Out!
The free site www.irishgenealogy.ie has images of civil birth records from 1864-1941, images for marriage records from 1870-1941 and images of death records from 1878-1966. NOTE images for marriages from 1864-1869 should be added very soon.
Below are links to the 1913 birth record for Martin which shows that his father was Martin and his mother Bridget was also a Crehan, followed by his parents 1905 marriage record showing Matthew as the father of Martin , followed by the 1869 civil birth record for Martin showing his mother was Catherine Fallon, followed by a transcription of his parents church marriage record in 1860 (from the subscription site Roots Ireland, followed by the 1855 Griffiths Valutation head of household listing for Killian civil parish which shows a number of Crehans including three in Rushestown: Mary, Matthias and Thomas. In addition, there was a Patrick Creaghan in Rushestown. Possibly, the Matthias was the the Matthew who married in 1869.
Finally, I also found an 1830 baptismal record for a Matthew Creaghan in Ballygar. See transcription below showing a father John. This 1830 record may be for your ancestor.
Let me know if you have any questions.
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_retur…
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_re…
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_retur…
Date of Marriage:18-Feb-1860
Parish / District:BALLYGAR
County:Co. Galway
Husband MatthewCreaghan Address Rushestown
Wife CatherineFallonAddress:Rushestown
https://www.failteromhat.com/griffiths/galway/killian.htm
Name:Matthew CreaghanDate of Birth:
Date of Baptism:06-Jun-1830Address:
Parish/District:BallygarGender:
CountyCo. Galway
Denomination:Roman Catholic
Father:John CreaghanMother:Ellenora CunninghanOccupation:1
Sponsor 1 /
Informant 1:Matthew Creaghan Sponsor 2 /
Informant 2:Ellenora Creaghan
ADDITIONAL INFORMATION Area: RUSHESTOWN.
