In 1901, as per the Census, there was 25 households listing Brennan/Brennen as Head of the house in County Longford. Six of the families who included Brennan/Brennen lived in the District Electoral Division of Cashel West.
My Great Great Grandmother Bridget Brennan was aged 72 and lived with my great grandfather Thomas on Clawinch Island.
Patrick Brennan aged 60 lived in Fortwilliam with his wife Delia and his 6 children.
Mary Brennan, a widow, lived in Drumnee with her son and daughter.
Ellen Brennan, a widowed shopkeeper in Cullentragh lived with her brother John Connaughtin and her children Michael and Mary Brennan.
James Brennen, lived in Claras and his wife Mary and their daughters.
James Brennen, his brother John, and 2 children lived in Cornadowagh
By 1911, at the time of the next Census, great great grandmother Bridget has died and Thomas is living on the island with his wife Margaret and their children.
Patrick Brennan of Fortwilliam has also died and his wife Delia lives there with 3 of her children.
In Drumnee, Mary Brennan has died and her son James is now the head of the household and lives with his sister Kate.
Ellen Brennan of Cullentragh is still living with her brother and two children though she is now listed as head of the household.
In Claras, Mary Brennan the wife of James has died and he is living with his 4 daughters.
James Brennan of Cornadough continues to live with his 2 children and his brother John.