The Viking at Drumshee — Cora Harrison

Living rough and fighting the invading Vikings, Brian Boru has no more money to feed his troops, and the Vikings at Limerick have a hoard of looted treasure, but it s closely guarded....

Fourteen-year-old Conn, from Drumshee, is the youngest soldier in Brian Boru's makeshift army. After a hard battle, he and his men retire to Drumshee to rest; on the way, Conn captures a Viking boy named Ivar. The two boys and Conn's sister, Emer, become friends.

Brian Boru has no more money to feed his troops; the Vikings at Limerick have a hoard of looted treasure, but it's closely guarded. The Emer has an idea; why not use Ivar's boat-building skills, make a Viking style boat, and attack Limerick by the unguarded sea route. Boru puts the plan into action and with all three children playing a crucial part they seize enough treasure to put the army back on its feet.

The book ends with Conn and Ivar becoming captains in Brian Boru's army and Emer and Ivar getting married.