From as early as the first century AD the invading Romans saw its advantages and quickly built a fort to protect the anchorage.  In fact Holyhead was significant enough to be used, in 1332, as a major mustering point for a military expedition to Ireland. Yet despite these clear advantages, for a long while Beaumaris was still regarded as the premier port on the island - sitting at the south east corner it was, at least, better protected from the elements - and it was not until the growth of the mail service between London and Ireland in the early 19th century that Holyhead really began to assume a dominant position. 

Later in Elizabeth I’s reign several temporary Mail Services were set up with the growing unrest in Ireland over the religious reforms. Both Beaumaris and Holyhead were made temporary posts lasting for around a year at a time through 1560’s to 1590’s. Throughout this troubled period the mail was sometimes landed anywhere not necessarily in the home ports. In 1815 a select committee report recommended building a landing place at Porth Dafarch which was eventually constructed by 1819; its use was short lived with the introduction of the steam packets on 31st May 1821. 

The Act of Union 1800, which unified Great Britain and Ireland, gave rise to a need to improve communication links between London and Dublin. A Parliamentary committee led to an Act of Parliament of 1815 that authorised the purchase of existing turnpike road interests and, where necessary, the construction of new road, to complete the route between the two capitals. This made it the first major civilian state-funded road building project in Britain since Roman times. Responsibility for establishing the new route was awarded to the famous engineer, Thomas Telford.

From Bangor the road crosses the Menai Suspension Bridge to Anglesey and then runs roughly parallel to the A55 expressway to the outskirts of the village of Valley where the A5 continues onto the Stanley Embankment. The A5 from Valley to Holyhead is named London Road running through to the Port of Holyhead. The A5 terminates at Admiralty Arch (1822–24), which was designed by Thomas Harrison to commemorate a visit by King George IV in 1821 en route to Ireland and marks the zenith of Irish Mail coach operations.

With the coming of the railways, the Grand Junction Railway and the London and Birmingham Railway co-operated to run fast trains from London to Liverpool. Fast steam packets ran from Liverpool to Kingstown (as Dún Laoghaire was then known), giving a total journey time of 22.5 hours from London to Dublin. From 24 January 1839 the Irish Mail contract was switched from Holyhead to Liverpool.

Even before this date the search was on for the shortest route from Dublin to London and this was clearly via Porth Dinllaen on the Llŷn Peninsula. But survey engineers quickly found difficulties in the terrain that might have outweighed any advantages of distance, however they saw this simply as a challenge to be overcome. The great advocate of Porth Dinllaen was Henry Archer, Secretary of the Ffestiniog Railway Company, who engaged the services of Charles Vignoles to survey the route in 1835, although Vignoles produced three alternative routes.

Isambard Kingdom Brunel chose quite a different route and was actively surveying via Gloucester and New Quay in Cardigan Bay. Others promoted the merits of the proposed St George's Harbour constructed with a large stone breakwater between the Great Orme Head and the Little Orme Head in Ormes Bay at Llandudno and they were the first to petition Parliament, in 1837, with their St George's Harbour and Railway Bill, which failed.

It was against this background that plans for a Chester and Holyhead Railway were prepared and canvassed between 1838 and 1842, almost scuppered in 1843, and eventually given Royal Assent on 4 July 1844 (7 & 8 Vic. cap. lxv).

On 1st August 1848 the Chester and Holyhead Railway opened to Holyhead, and ship passengers bound for Ireland were taken through the town by Robert's horse bus to pier had three timber jetties and one of stone from where the Cambria and the steamers went to Ireland in about four hours. The Anglia and the Hibernia also came into service before the end of 1848. The Act of 1847 gave powers for a new packet pier construction to be built as part of government proposals for a large refuge harbour. 

 

A link to a 1899 Ordnance Survey Map of the Porth y felin area (These are all copyrighted by the Frith Collection)

There was much need for a new harbour. The Admiralty Pier at the Northern end of the harbour near the entrance from which the railway and City of Dublin steamers embarked and disembarked their passengers was very heavily used. It was exposed in bad weather with the water alongside needing frequent dredging. Considerable congestion would occur in the harbour as ships would try to find shelter when bad storms hit James Meadows Rendel was the engineer for the new refuge. He proposed a north and east breakwater in conjunction with an inner steam packet pier on the north shore, on the other side of the town to the old harbour. Construction began in January 1848. With the expectation of more traffic coming to the Port when it was opened, plans were made for a railway extension between the station and Admiralty Pier. 

The sea/rail service left a lot to be desired at first until an angry travelling rail director, displeased with the service, gave orders that a refreshment room be provided at the temporary station. In 1850 it was decided that there should be a permanent station at Holyhead. The railway extension at Admiralty Pier opened on 20th May 1851 and the opening of the new station in September of that year, with passenger comfort being assured by the opening a permanent refreshment room and by the purchase by the railway of the Royal Hotel, which had hot & cold shower baths and was fitted with a style of elegance in every way for the highest grade of people in Society. 

The new station was described as "commodious and extensive".Rendell died before the harbour was finished, and his work was taken on by Sir John Hawkshaw. One month after Rendell's death Brunel's ship the came to Holyhead on a trail trip to see if the new harbour would be a suitable place from where she could depart for her fist transatlantic crossing. Had this been the case special reduced tickets from London were to be available. There was great interest in this project. So much to in fact, that Gladstone (then Chancellor of the Exchequer), railway and steamship directors and officers of the Royal Hotel attended a banquet (especially laid on for the occasion) took the French Prince Napoleon around the vessel. Fifteen excursion trains arrived at the station in one day! Sadly, however, the Great Eastern was too large and there wasn't enough "sea room" for comfort. She sailed for Southampton and did not visit Holyhead again. 

In the next couple of years the LNWR developed the inner harbour with a large goods shed and berthing facilities on the west shore, opened on 1st January 1866, and enlarged in 1870 with a new platform and waiting room the LNWR steamers. In 1873 a new greeore service required massive dredging operations, a new large warehouse on the east quay and a wonderful new station and five-storey, 65 bedroomed red-bricked Station Hotel(opened on 17th June 1880). The platforms (the west being 1,260ft long, and the east being 1,130ft long) were divided by the angle which meant that passengers could transfer from train to ship with greater ease, and each quay could berth two ships. The station was opened by the Prince of Wales and a large clock was built to mark the occasion. From 1902 the LNWR service continually improved in comfort and speed, but had a rival for Irish traffic from the Fishguard/Rosslare Irish Sea crossing route. Therefore the Holyhead/Dun Laoghaire route was highly publicised, including the publishing of a guide to Holyhead and the new hotel. The successful berthing of White Line's Liner the "Cedric" in 1909 gave the Port publicity a great boost. White Line decided that ships on the Liverpool-New York run could call at Holyhead saving many hours on the London connection, for rail passengers. In 1909, the Line announced that Liners Laurentic and Megantic in the Canadian trade would call at the Port with a possibility of the Olympic and Titanic Liners coming to Holyhead too, but due to bad weather conditions and with fewer passengers taking advantage of the time saving crossing, sadly in 1910 the liners stopped coming to the Port.

Success transferred instead to the GWR Fishguard Port from which the Cunard line began to operate. All was not lost however because in 1920 the LNWR achieved the sea mail contract and did this with four new steamers from Holyhead. The railways were nationalised in 1948 now being known as British Railways. The new motor vessel the Slieve Donard was introduced in 1954. It was designed to carry cattle and containers. Also in the 1950's a new import/export warehouse was built. The Holyhead Ferry 1 entered service in Holyhead in 1965. She was able to ferry 150 cars and 1,000 passengers. In 1968 a new container service operated between Holyhead the and Dublin Container Terminal on the m.v.Harrogate, with the Darlington and Selby ships also running when required. A fully automated, high-capacity service was brought into operation at Holyhead to be operated by two new cellular container ships, with freightliner trains linking with Sheffield, Nottingham, Manchester, Leeds, Birmingham and London with connections to Stockton and Cardiff via Zeebrugge and Harwich, Rotterdam, and European Services. The Brian Boroime and Rhodri Mawr were on the new service in 1970, taking up to 3,000 tons of containers. The Britannia bridge (across the Menai Straits) burnt down The Brian Boroime and Rhodri Mawr were transferred to Haysham for the Belfast service. The Dublin service was operated by the Isle of Ely and the MV Harrogate as necessary, and the containers transferred to Caernarvon, from where about 45 containers were transported daily by road to Holyhead. Other containers were also transported from Bangor and Gaerwen. In November 1970 Irish livestock traffic began again with over 105,000 leaving Holyhead by road to Menai Bridge. When the Britannia Bridge re-opened, the people of Holyhead celebrated with fireworks - the sounding of ship's hooters and the cheering crowds welcomed the Cambria ship into Holyhead at the end of January 1972. The Holyhead Ferry 1 was replaced by two ships in 1973, called the Lord Warden and Duke of Rothsay. In the mid 1970's the port provided all year-round car ferry services. A new terminal was built and improvements were made to the Customs hall, mail and baggage facilities with facilities being extended to motor vehicles. In May 1977 the new passenger ro-ro roll-on/roll-off) 8,000 ton ship the St. Columba commenced two sailings daily to Dun Laoghaire. The Columba could carry 325 cars, 2,400 passengers. The Avalon acted a a summer relief ship. The Station Hotel was demolished in 1978, to make way for a new modernised station complex comprising of a booking office, waiting rooms and a buffet. In August 1981, a second vessel called the St. David was introduced on the route. She could carry 1000 passengers and 309 card or 62 commercial vehicles. 

Privatisation came in 1984 when James Sherwood of Sea containers bought Sealink and traded under the name of Sealink British Ferries. In 1991 the Freightliner terminal closed and Stena Line doubled in size in 1990 with the acquisition of Sealink British Ferries from Sea Containers. This first became Sealink Stena Line, then Stena Sealink Line and finally Stena Line (UK), which now operates all of Stena's ferry services between Great Britain and Ireland.

In 1993 Stena Line modernised the port, by building a new passenger terminal and a Duty Free shop for car passengers on shore. They also introduced new faster ferries to the route, the first being the Stena Lynx 1 catamaran.She could carry 450 passengers and 85 cars In June 1994 a bigger catamaran was introduced to the Holyhead/Dun Laoghaire route - the Stena Lynx 11. She could carry 650 passengers, and with a lower and upper car decks she could take 110 cars. The World’s LARGEST catamaran called the Stena Line High Speed Sea-Service (HSS) Explorer began service on the Holyhead/Dun Laoghaire route in April 1996. She could carry 1500 passengers, 375 cars, or 100 cars and 50 Articulated lorries. 

British & Irish Line ( B & I ) were bought out by the "Irish Ferries" Company and the process began in the late 1980's. They introduced a brand new ferry to the Holyhead - Dublin route in 1995 called the Inishfree. Another brand new and much bigger ship was introduced to the route in 1997 called the Inishmore. She is 33,000 tons, and is the largest ferry to run on the Irish Sea, and the largest in northern Europe. She can carry 2300 passengers and can carry in excess of 400 cars. This vessel takes three and a half hours to cross from Holyhead to Dublin.This vessel is called the Jonathan Swift, named after the author of Gulliver's Travels. As its name suggests, it is a new fast craft that the Irish Ferries Company is to introduce to the Holyhead - Dublin route in 1999. She will carry 800 passengers and about 200 cars. for more information about the DUBLIN SWIFT!

At one time subservient to Beaumaris as the region's main port, Holyhead came into its own in the early 19th century, when Thomas Telford built a new road to connect north Wales with London. The Admiralty Pier was constructed in 1821, and was used by the City of Dublin Steam Packet Company. The so-called "Irish Mail Line" of the Chester & Holyhead Railway ran from Holyhead railway station to the pier. The Admiralty Arch was built in 1824, marking the end of Telford's new road.[5] The arch was designed by Thomas Harrison and its main purpose was to commemorate the visit of King George IV of the United Kingdom in 1821, when he set sail from Holyhead on the royal yacht, on a state visit to Ireland. In 1845, an Act of Parliament led to the construction of the new port, and a new railway station was opened in 1851.[3] In 1853, Queen Victoria of the United Kingdom arrived in the port of Holyhead with the royal party, including her consort Prince Albert and two of her sons, including the young Prince of Wales.[7] The breakwater was completed in 1873,[8] and was declared open by the same Prince of Wales, now an adult, who officially opened the New Harbour on 17 June 1880. A new station hotel was erected at about the same time. However, as a starting point for sea journeys to Ireland, Holyhead soon had a rival, as the port of Fishguard began operating ferries in 1906.[3][9] In 1916, a naval base was created and the Irish Sea Hunting Flotilla was established later in the First World War to combat U-boats operating in the Irish Sea.[5] During the 1930s, a trade war with the newly established Republic of Ireland had an adverse effect on the level of use of the port, which caused widespread unemployment in the town of Holyhead. During the Second World War, however, the Royal Dutch Navy began using the port as a base. In June 1939, the Royal Navy submarine HMS Thetis sank during sea trials in Liverpool Bay and it was subsequently brought to the harbour at Holyhead after being beached at Traeth Bychan. It remained at Holyhead in dry dock while the contents were removed; fourteen of the 99 victims were buried locally. A new container port opened at Holyhead in 1970, the container service between Holyhead and Dublin having begun two years earlier. Major changes were made to the port facilities, and the station hotel was demolished in 1978. Bigger ferry vessels came into use, and the Stena Lynx 1 catamaran began services in the early 1990s. In the late 20th century, the port was owned by Sealink (later Stena Sealink), a ferry company which ran a fast ferry from the Admiralty Pier and slower ferries from an alternative berth. The Irish ferry company B&I also operated ferries to and from Ireland from the port of Holyhead. B&I took Sealink to court in 1992 for imposing less favourable conditions on its competitor when using the port. In the following year, another company, Sea Containers Ltd, took legal action against Sealink Ports on similar grounds. Stena Line discontinued its fast ferry service in 2015, leaving Irish Ferries operating the fastest service between Holyhead and Dublin.