There are 6 books in the Celtic World of Morgan Llywelyn series. The newest book is The Wind from Hastings which came out in 1978.

2
Finn Mac Cool

Finn Mac Cool
A great legendary hero of ancient Ireland, Finn Mac Cool comes vividly to life in an enthralling historical fantasy of love, betrayal, magic , myth, and war. By the author of Lion of Ireland. 100,000 first printing. Tour.

3
Brendan

Book cover of Brendan
This is the story of Saint Brendan the Navigator, whose legendary quest to find the Isle of the Blessed is one of the most remarkable and enduring of early Christian tales. Among Irish saints, Brendan the Navigator is second only to Patrick. Founder of several Christian monasteries, he most famously…

5
Pride of Lions

Pride of Lions
In the sequel to Lion of Ireland, Donough, Brian Boru's young son, copes with grief over his father's death, a first military command, his treacherous mother, passion for a beautiful pagan, and his struggle for acceptance as High King of Ireland. 125,000 first printing. $125,000 ad/promo.

6
The Wind from Hastings

The Wind from Hastings
Presents a fictionalized account of the fate of Aldith, the wife of King Harold, who, at the defeat of her husband at the hands of William the Conqueror, disappeared with the legitimate heirs to the English and Welsh thrones