[2] Thomas Roberts was an active member of Gwyneddigion, a society of Welsh patriots founded in London in 1770 as a Welsh-language debating society that discussed the controversial issues of radical London politics at a time of insecurity and censorship.
In 1798, Roberts published the book Cwyn yn erbyn Gorthrymder (A Complaint Against Oppression).
[4] The pamphlets used English to brand expressions and people as hostile to Wales and the Welsh language.
To ensure that Wales benefited from many of the works previously available in English, Roberts published a Welsh version of Benjamin Franklin's Poor Richard's Almanack in 1839.
[5] Roberts joined in challenging the clerical privilege enjoyed by the Established church and wrote against the civic inequalities experienced by the dissenters of Methodism in 18th-19th century Wales.
His pseudonymous writing as Arvonius spoke against the libelous anti-Methodism of a fellow London-Welshman, Anglican Edward Charles.