In the fourteenth-century Dublin was a small walled city with perhaps 10,000 inhabitants. At this time Grangegorman functioned as one of three home farms, the others being Glasnevin and Clonken or Clonkene (now known as Deansgrange), which served to meet the expenditure of the Prior of the Augustinian Priory at The Church of the Holy Trinity. The Canons of this priory served The Church of the Holy Trinity, which was the State Church until the dissolution of the monasteries in the sixteenth-century when it was re-established as Christ Church Cathedral. The farm buildings at Grangegorman consisted of one large hall with some rooms attached and an enclosed farmyard around which there stood a barn, a malthouse, a workshop and a haggard (a farm enclosure for stacking grain or hay, etc.). All of these buildings had thatched roofs. The Manor of Grangegorman was located in the north end of Stoneybatter in present day Manor Street. It is from this association that Manor Street derives its name. The poorly paid farm labourers of Grangegorman farm lived in cottages near the manor.
The territory of Grangegorman has had a long association with orchards which only passed into history in the mid-nineteenth century. The lease of Grangegorman dated 1485 refers to its lands as "the Orchard". With the dissolution of the monasteries, King Henry VIII on 10 May 1541 by letters patent authorised the transformation of the Prior and Canons of Christ Church to a Dean and Chapter. The lease granted that same year refers to "the Great Orchard" and in 1542 to "an orchard belonging to the Dean situate beyond the town of Oxmantown Green". In 1560 the lease simply referred to "the Dean's Orchard".
The possession of the Manor of Grangegorman passed into the hands of Rt. Hon. Francis Agard after the formation of Dean and Chapter for the management of Christ Church Cathedral. Following Agard's death in 1577, this possession passed to the control of his son-in-law, Sir Henry Harrington. In the period after the Restoration, the residential expanse of Grangegorman consisted of forty houses. The Manor House at this time was held by Sir Thomas Stanley. It is assumed that the domicile to which the now defunct Stanley Street once led was the manorial house. This site is currently occupied by the Stanhope Street Convent of the Irish Sisters of Charity. In 1674 the Manor of Grangegorman was held by Sir John Stanley (the son of the previous owner). In the early eighteenth-century it passed to Charles Monck who was Stanley's nephew and an ancestor of Viscount Monck, the Earl of Rathdown who was the landlord holding most of the property in the area.