This record is the only known act of the king on the Continent.Having successfully dealt with this considerable number of disaffected magnates, the twelfth–thirteenth-century Chronicle of Holyrood and Chronicle of Melrose reveal that Malcolm launched three military expeditions into Galloway.The most important of these mid-century colonial establishments were: Annandale for Robert de Brus (died 1142); Upper Eskdale and Ewesdale for Robert Avenel (died 1185); Lauderdale and Cunningham for Hugh de Morville (died 1162); Liddesdale for Ranulf de Sules (died 1165×1172); and Mearns, Strathgryfe, Renfrew and North Kyle for Walter himself.In 1161×1162, Malcolm confirmed Walter's stewardship, and confirmed David's grants of Renfrew, Paisley, Pollock, "Talahret", Cathcart, Dripps, Mearns, Eaglesham, Lochwinnoch and Innerwick.
The latter region was largely Welsh-speaking at the time, and it is possible that this languages was then mutually intelligible with Breton, Cumbric.
In fact, Walter and the other colonial lords settled in western Scotland were probably intended to protect the Scottish realm from external threats located in regions such as Galloway and the Isles.
In 1164, Somairle mac Gilla Brigte, King of the Isles invaded Scotland and was defeated near Renfrew.
There is reason to suspect that Walter took part in the Siege of Lisbon against the Moors in 1147.
He probably assisted Malcolm in the series of Scottish invasions of Galloway in the 1160, which resulted in the downfall of Fergus, Lord of Galloway.