The barony of Garscadden was first recorded in possession of the Fleming's of Biggar. The Flemings were supporters of Robert the Bruce in the Wars of Independence and King Robert had ceded Kirkintilloch to Malcolm Fleming as part of a forfeiture of the lands of Comyn. Malcolm's second son, Patrick Fleming, exchanged Garscadden and some other lands to obtain the lands of Board near Croy in 1369. The Erskines were the recipients of Garscadden, Sir Robert Erskine adding to his estate in Renfrewshire. The deal was witnessed by some of the leading noblemen of Scotland - among them the grandson of Robert the Bruce; Robert, the High Steward, later to become King of Scotland 1371-90.
Sir Robert Erskine was an Ambassador both to England and France. He and other noblemen ratified the succession of King Robert II to the crown. Both the post of Ambassador to England and the estate of Garscadden were handed down to his son, Sir Thomas Erskine.
Sir Thomas' son , another Sir Robert, succeeded to the barony. He became one of the hostages for the ransom of King James I and he later passed the estate to the Galbraiths in 1444. The building of Garscadden chapel was probably later than this date.
As with the Craufurds of Drumry, the Galbraiths would have similarly been obliged to build a barmkin and Peel tower following the 1535 Act of Parliament.