Background
Brennan was born at Tipperary, Ireland, and ordained to the priesthood at Brixen-Tyrol on July 4, 1880.
Brennan was born at Tipperary, Ireland, and ordained to the priesthood at Brixen-Tyrol on July 4, 1880.
He was consecrated Bishop of Dallas at Erie, Pennsylvania, on April 5, 1891, by Bishop Tobias Mullen. Two years later, on February 1, 1893, he was transferred to the titular see of Utilla, and was made Auxiliary to Bishop Thomas Joseph Power of Saint John"s, Newfoundland. He was called to Rome in December 1904, and was given the titular see of Cesarea on October 7, 1905.
The last years of his life were spent in the Basilian monastery at Grottaferrata, near Rome, where he died at age 60.