Thomas has placed the walled town of Youghal in the category of major second-order towns in Ireland. Similar to towns such as Kilkenny and Galway, Youghal can date the construction of its walls to approximately 1250. This classification is based on the premise that Youghal is an Anglo-Norman foundation. As far as the current archaeological evidence is concerned this is true, the earliest upstanding remains are from the period of the Anglo-Norman colony. The impetus for urban development at Youghal possibly came about because of the establishment of a Viking/Hiberno-Norse longphort in the mid-9th century. The site offered good defensive, commercial and logistical characteristics for the Norman invaders and developed accordingly under the patronage and lordship of the Earls of Desmond.
Youghal received its charter of incorporation in 1209 but it was after 1215 that development began in earnest. Maurice FitzGerald II obtained possession of Youghal in 1215 and began to colonize the town with people from Bristol, southwest England and Wales. For the lords of Inchiquin, Youghal would function as the principal town of the barony, primarily serving a militaristic and strategic function. The purpose was to consolidate the Anglo-Norman hold on the area, but this function would be superseded by the economic and commercial role of the town.
The town developed throughout the 13th century, establishing itself as an important part of the commercial infrastructure of the province, forging links with inland towns and markets. By the mid-14th century, it had developed as an affluent walled port town, with trading links throughout Europe. The town experienced a severe downturn in the 14th when 40% of the population succumbed to the Black Death. The town did begin to recover towards the end of the 14th century and enjoyed a prime position as one of the Cinque Ports of Ireland from 1462. During the upheaval of the 16th century, Youghal was sacked by the Earl of Desmond in 1579. During the Munster Plantations, it was granted to Sir Walter Raleigh and was subsequently acquired by Richard Boyle, future Earl of Cork. In the 17th century the town re-established itself as an important trading port, a position it maintained throughout the 18th and early 19th centuries.