Goslyn’s early background remains obscure, although it appears from his will that he had relatives in Alconbury Weston, Huntingdonshire, a village towards which he clearly felt a strong sense of personal attachment. He also had less obvious connexions with Bromley in Middlesex and Writtle in Essex. He first appears as one of the executors appointed by John Weston, a London merchant, in July 1407, having evidently established himself in the City by then. Goslyn shipped two modest consignments of cloth into the port of London three years later, but did not otherwise show much interest in this branch of commerce. The few surviving references to his business affairs show that he dealt chiefly in iron, and on at least one occasion he supplied the wardens of London Bridge with a quantity of it for their building works. He also trained a number of apprentices, two of whom were learning their trade as ironmongers with him when he died.
Although he did not play as full a part in civic life as some of his contemporaries, Goslyn rose to the rank of alderman, and twice, in 1419 and 1423, he attended the parliamentary elections held at the Guildhall. In June 1423 he was called upon to arbitrate in a mercantile dispute being heard before the mayor and aldermen of London. Two years later he helped to assess a tax imposed by the authorities upon brewers, poulterers and hucksters trading in the City. Goslyn begged to be excused from his aldermanry in October 1426, but his petition was dismissed as unreasonable, and he continued to shoulder the responsibilities of office until shortly before his death. Meanwhile, in April 1428, he was appointed by the common council to act as one of the receivers of the £2,000 being lent by the people of London to Henry VI.
Goslyn died between 13 Oct. 1428 and 3 Jan. 1429, leaving instructions for his burial in the church of St. Mary at Hill ‘without pomp or vainglory’. To the six children of his second marriage, all of whom were under age, he bequeathed a cash sum of £480, which was raised to £500 by his executors on the birth of Robert, his posthumous son. Over £104 was set aside for friends and kinsmen as well as for the many charitable and pious works by which Goslyn hoped to be remembered. His widow, who acquired a life interest in most of his property, remarried in June 1431. In the following year her second husband, the fishmonger John Bedham, obtained custody of his seven stepchildren, together with £400 of their inheritance.
