Madog ap Maredudd had died in 1160, enabling Owain Gwynedd to regain territory in the east.

He had formed an alliance in 1163 with Rhys ap Gruffydd of Deheubarth to challenge English rule.

Henry II, who has ordered the reconstruction of a number of fortresses in the Welsh marches, gain invades Gwynedd in 1165, but instead of taking the usual route along the northern coastal plain, the king's army invades from Oswestry and takes a route over the Berwyn hills.

The invasion is met by an alliance of all the Welsh princes, with Owain as the undisputed leader.

However, apart from a small melee at the Battle of Crogen there is little fighting, for the Welsh weather comes to Owain's assistance as torrential rain forces Henry to retreat in disorder.

The infuriated Henry mutilates a number of Welsh hostages, including two of Owain's sons.

Henry now has additional fortresses built.

Rhys ap Gruffydd, Prince of Deheubarth, had had other reasons for rebellion when all the Welsh princes had united in 1164 in an uprising against Henry II, for he had returned to Deheubarth from England to find that the neighboring Norman lords were threatening Cantref Mawr.

His nephew, Einion ab Anarawd, who was the captain of his bodyguard, had been murdered at the instigation of Roger de Clare, Earl of Hertford.

The murderer had been given the protection of the Clares in Ceredigion.

Rhys had first appealed to the king to intercede; when this failed, he had invaded Ceredigion and recaptured all of it apart from the town and castle of Cardigan.

The Welsh revolt had led in 1165 to another invasion of Wales by King Henry.

Henry had attacked Gwynedd first, but instead of following the usual invasion route along the north coast he attacked from the south, following a route over the Berwyn hills.

He was met by the united forces of the Welsh princes, led by Owain Gwynedd and including Rhys.

Torrential rain had forced Henry's army to retreat in disorder without fighting a major battle, and Henry had vented his spleen on the hostages, having Rhys's son Maredudd blinded.

Rhys's other son, Hywel, was not among the victims.

Rhys had returned to Deheubarth where he captured and burned Cardigan Castle.

He had allowed the garrison to depart, but held the castellan, Robert Fitz-Stephen, as a prisoner.

Shortly afterwards, Rhys captured Cilgerran castle.

The King of Leinster, Diarmait Mac Murchada, deprived of his kingdom by the High King of Ireland, had asked Rhys ap Gruffydd in 1167 to release Robert Fitz-Stephen from captivity to take part in an expedition to Ireland.

Rhys had not obliged at the time, and the exiled king had gone from here to England and Aquitaine in France in order to have the consent of King Henry II of England to recruit soldiers.

Rhys had released Fitz-Stephen the following year.

Richard de Clare—called, like his father, Strongbow—is the son of Gilbert de Clare, first Earl of Pembroke, and Isabel de Beaumont.

Richard's father died in about 1148, when he was about eighteen years old, and Richard had inherited the title Earl of Pembroke.

It is probable that this title was not recognized in 1154 at Henry II's coronation.

As the son of the first Earl, he had succeeded to his father's estates in 1148, but had been deprived of the title by King Henry II of England in 1154 for siding with King Stephen of England against Henry’s mother, the Empress Matilda.

Richard is called by his contemporaries Earl Striguil, for his marcher lordship of Striguil where he has a fortress at a place now called Chepstow, in Monmouthshire on the River Wye.

He sees an opportunity to reverse his bad fortune in 1168 when he meets Diarmait Mac Murchada, the deposed King of Leinster.

Fitz-Stephen, on returning to Wales, had helped Diarmait Mac Murchada to organize a mercenary army of Norman and Welsh soldiers, including Richard de Clare, second Earl of Pembroke, alias Strongbow.

The first Norman knight to land in Ireland had been Richard fitz Godbert de Roche in 1167, but it is not until May 1, 1169, that Robert leads the vanguard of Diarmait Mac Murchada's Cambro-Norman auxiliaries to Ireland, thereby precipitating the Norman invasion of Ireland.

The main invasion party lands near Bannow strand, County Wexford with a force of thirty knights, sixty man-at-arms and three hundred archers.

The next day, Maurice de Prendergast lands at the same bay with ten knights and sixty archers.

This force merges with about five hundred soldiers commanded by Diarmait.

In return for capturing Wexford, MacMurrough grants Fitz-Stephen a share in two cantreds, Bargy and Forth which comprises all the land between Bannow and the town of Wexford.

The cantreds are to be held jointly with Maurice FitzGerald, Lord of Lanstephan, his half-brother.

The Siege of Wexford lasts only two days.

The first attack is repulsed at the loss of eighteen Normans and three defenders.

These are believed to have been the only deaths during the siege.

Fitz-Stephen then orders his men to burn all the ships in the town's harbor.

The next morning, the attack on Wexford begins again.

Shortly afterward, the defenders send envoys to Diarmait.

The defenders agree to surrender and renew their allegiance to Diarmait.

It is claimed that they were persuaded to surrender by two bishops who were in the town at the time.

He is accompanied at the siege by Robert de Barry, the eldest son of his half-sister Angharad de Windsor. (Nest then, is the mother of Robert, Maurice and Angharad.)

Within a short time, Leinster has been conquered, and the Viking-established towns of Wexford, …

…Waterford and …

…Dublin are under Diarmait's control.

Henry has allowed the expedition of barons from South Wales to establish Anglo-Norman supremacy in Leinster, but will later levy a fine of one hundred shillings on one Joyce of Gloucester for lending money to Strongbow for his expedition.

Joyce had done nothing illegal, but Henry is nervous about the use of Jewish loans to finance any independent actions or policies.

Rhys benefits in 1169 and 1170 from the Norman invasion of Ireland, which is largely led by the Cambro-Norman lords of south Wales.

The departure of the Norman lords enables Rhys to strengthen his position, and the death of Owain Gwynedd in late 1170 leaves him as the acknowledged leader of the Welsh princes.

Strongbow himself arrives in August 1170.

He soon marries Diarmait's daughter, Aoife, and is named as heir to the Kingdom of Leinster.

This latter development causes consternation to Henry II, who fears the establishment of a rival Norman state in Ireland.

Accordingly, he resolves to visit Leinster to establish his authority.

Diarmuid Mac Murchada dies in May 1171, and his son, Donal MacMurrough-Kavanagh claims the kingdom of Leinster in accordance with his rights under the Brehon Laws.

The Earl of Striguil also claims the kingship in the right of his wife.

The old king's death is the signal of a general rising, and Richard barely manages to keep Rory O'Connor out of Dublin.

At this time, Strongbow sends his uncle, Hervey de Montmorency, on an embassy to Henry.

This is necessary to appease the King, who is growing restive at the Earl's increasing power.

Upon his return, de Montmorency conveys the King's terms—the return of Strongbow's lands in Normandy, England and Wales as well as leaving him in possession of his Irish lands.

De Clare in return surrenders Dublin, Waterford and other fortresses to the King.

Henry lands with a large fleet at Waterford in 1171, becoming the first King of England to set foot on Irish soil.

This marks the beginning of English and later British rule in Ireland.

Both Waterford and Dublin are proclaimed Royal Cities.