[1] The 5th laird's first wife (and cousin) was Lucy, daughter of David Barclay of Cheapside, a wealthy London merchant.
[3] Captain Barclay's most famous exploit took place between 1 June and 12 July 1809 at Newmarket, during which he walked 1 mile (1.6 km) in each of 1000 successive hours to win an initial wager of 1000 guineas.
The Times, which carried little general interest news, printed this report alongside an account of the campaigns of Marshal Soult in the Peninsular War (14 July): During the 42 days of this exercise his time per mile increased from 14 m 54 s to 21 m 4 s and his weight dropped from 13 st 4 lb (84.5 kg)(186 lbs) to 11 st (70 kg)(154 lbs).
In 1809 he served as aide-de-camp to the Marquess of Huntly on the ill-fated Walcheren Campaign, starting out just 5 days after the completion of the 1000-mile feat.
The only surviving child from his marriage was a daughter, Margaret, who had moved to America but eventually resettled in Great Britain and retired to Cornwall with her eldest son, also a Robert Barclay-Allardice (who later became Mayor of Lostwithiel between 1899-1901 and 1904-6).
The Lairdship of Ury, heritable only through the male line, passed to a third cousin, Charles Barclay, who lived in Surrey.