McSwiney, Peter Paul (c.1810–1884), draper and founder of the ‘New Mart’, was born in Cork city, son of John McSwiney (b. 1780) of Cork. Little is known of his early career other than that his family was part of the increasingly prosperous catholic middle class in Cork and that he was related to Daniel O'Connell (qv). In May 1852 McSwiney provided the financial backing to form a partnership in Dublin with draper George Delaney to open a store on Sackville St. (O'Connell St.). The partners purchased the leases of 23 to 28 Sackville St. and opened a competition for the design of the store. After some controversy relating to who should be credited with the design for the façade, McSwiney, Delaney & Co. opened the ‘New Mart’ on 28 May 1853. Decorated in an opulent style and selling fabrics, silks, and other finery, the store was far more impressive than anything witnessed in London, Paris, or New York at the time. McSwiney developed the idea of shopping as a form of entertainment. In doing so he arguably started what was the world's first department store several years before Bon Marché, which subsequently claimed the honour, opened its doors in Paris in the 1860s. The New Mart was an instant success and captured the imagination of the public, who affectionately referred to it as ‘the Palatial Mart’ and ‘the Monster Store’. Michael Angelo Hayes (qv), a relation of McSwiney by marriage, captured the position of the store as a focal point of the city's main boulevard in an 1854 painting of Sackville St.
The success of the enterprise raised McSwiney's profile, to the extent that he was elected a city councillor for the North Dock Ward and two years later lord mayor of Dublin (1862). On 8 August 1864 he took great pride in laying the foundation stone for the memorial round tower to his relation O'Connell at Prospect cemetery, Glasnevin. In 1866 he became an alderman and JP. Although he was personally a staunch O'Connellite, the DMP identified his firm as a breeding ground for the Fenian movement and he had to intercede on behalf of several employees who were arrested during this period.
In 1872 George Delaney retired and McSwiney formed a new partnership with Edward Russell, P. J. Plunkett, and Michael Lynch, called ‘McSwiney & Co.’, to run the store. That same year the partnership reputedly became the first publicly quoted company in the city, with McSwiney as its chairman. The store had continued to prosper throughout the 1860s and early 1870s and he renovated the interior to mark the Exhibition of Arts, Industries, and Manufactures that took place in Dublin. In addition to the fancy goods already stocked, the store began to carry goods from Germany, France, and Switzerland. At this time he helped to organise a public collection to help France meet its war debts following defeat by Germany. He was reelected lord mayor in 1875 and in his second term presided over the celebrations for the O'Connell centenary, during which he laid the foundation stone for the O'Connell statue. At a banquet in the Mansion House he showed his rejection of the policies of Isaac Butt (qv) when he called on the veteran Young Irelander Sir Charles Gavan Duffy (qv) to speak rather than Butt. He saw Duffy as the heir to O'Connell's Repeal Association and attempted to induce him to lead a new repeal movement.
During this period he had also become involved with the Dublin & Chapelizod Distillery through another relation, John Stanislaus Joyce (qv), father of James Joyce (qv). McSwiney invested a large sum of money, but the venture was unsuccessful and the firm was wound up in 1877. Despite these losses McSwiney spent another large sum on rebuilding and enlarging the store in 1878. The façade was extended from eight bays to eleven and absorbed the old structure of the Imperial Hotel, although the hotel remained a separate business. However, the following year saw a depression in the economy, and McSwiney's attempts to recapitalise with the introduction of new partners could not save the store. By 1882 the New Mart was bankrupt and McSwiney's health was in rapid decline. The receiver of the company, Robert Gardner (qv), sold the store to M. J. Clery (qv) of Limerick for £32,000, and it reopened as Clery & Co. in 1883.
For his services in aiding the French war debt he was received on an official visit to France by Napoleon III and was created a chevalier of the Grand Cross. For his services to the catholic cause he was also made a knight of St Gregory the Great. Michael Angelo Hayes painted his portrait, which was held by Dublin corporation. He died 27 February 1884 aged 74 years at 71 Lower Baggot St., Dublin.
He married Anne O'Lalor and lived at Westmoreland St, Dublin; they had three sons and six daughters.