From 1866, the man-of-war Thisbe, placed at the disposal of the Seamen's Mission by the Admiralty and moored in the Bute East Dock, served as a seaman institute and church for Cardiff Docks. By 1890, however, it was evident that this vessel, which had a capacity of only 150 people in the institute and a further 250 in the church, was no longer fit for purpose and plans for a purpose-built facility developed.

The building was designed by E. W. M. Corbett of Cardiff and constructed at a cost of £5,000, largely paid for by public subscription, including by local businesses and ships? crews, with the Bute Docks Company donating £1,000. The Marquess of Bute donated land for the site alongside the Bute West Dock Basin (Nprn 34288) and just inside of the gates of Bute Crescent, opposite the Mount Stuart Hotel (Nprn 18155). The building, constructed of ballast stone with brick facings and a red-tiled roof, resembled a large Gothic-style church externally, with buttresses, coped gables, and a northern belfry projecting from the roof. Internally, however, the building was divided into two floors with the ground floor containing the seamen's institute and reading room, accommodating 400 people, as well as the chaplain's room, caretaker's apartments and entrance hall. The first floor held a church for seamen of all nationalities, which could sit 450 people. The Seamen's Institute was formally opened on 19 November 1891 by Lady Anne Lewis (wife of Sir W. T. Lewis, first Baron Senghenydd). The Seamen's Church was dedicated to All Souls by the Bishop of Llandaff on the following Wednesday (25 November).

The building underwent a thorough renovation at a cost of £750 in 1906 and was reopened by Viscount Tredegar on 1 May of that year. In the 1950s the building was occupied by the analytical chemists, Treharne & Davies Ltd and renamed Merton House. It was demolished in April 1987 as a part of wider redevelopment of nearby Bute Place, Bute Crescent, and Bute Street.

(Sources: NMR Site File Glam/Ecc/ST17SE; David Webb, `Demolishing Merton House, Cardiff? (Glamorgan Archives: Discovering Glamorgan's Past); Welsh Newspapers Online: Western Mail, 20.08.1890; South Wales Daily News, 20.11.1891, 26.11.1891; Cardiff Times, 21.11.1891; Weekly Mail, 12.05.1906)
A.N. Coward, RCAHMW, 04.06.2018