While in Swansea, Thomas became engaged to Ann Bowen. She died in 1853, at the young age of twenty, which became a source of poetic inspiration to him. At the suggestion of
Lady Llanover, he took his
bardic name from
Mynyddislwyn, the mountain above his home. Subsequently he was a regular winner of local
Eisteddfod prizes from the 1850s onwards. The best-known poem of Thomas is entitled
Y Storm (
The Storm), a long philosophical poem over 9,000 lines long. His poems are noted for their confident expressions of Christian faith, expectation of reunion in heaven, fulfilment of Christian duty and completion of a life fulfilled in God's work. He began preaching in 1854. And he was ordained a
Calvinistic Methodist minister in 1859. However, he never took charge of a chapel as was the custom with the Calvinist Methodists at the time. Daniel Jenkyns remained minister of Babell Chapel,
Cwmfelinfach. But Thomas was a regular preacher there for more than 20 years while undertaking his ongoing work. In 1864 Thomas married Martha Davies, Ann Bowen's stepsister. He edited several periodicals, the Welsh column of the
Cardiff Times,
South Wales Daily News and
Gwladgarwr. Thomas died from
bronchitis in
Ynysddu in 1878. He is buried in Babell Chapel,
Cwmfelinfach, where there is a monolith to his memory. ==The Islwyn Memorial Society==