The Lothians and Border Horse started numbering from 1 when it was formed out of its Imperial Yeomanry predecessor in April 1908. Charles Walter Grieve was given the new number 262 when he signed up on the 4th May 1908. In fact he was already a serving member with the Lothians and Border Horse Imperial Yeomanry and had been given the number 371 when he originally enlisted as 20-year-old in 1903. Then, his trade had been given as "Gentleman".
The regiment formed part of the Lowland Mounted Brigade which was administered from Edinburgh. Its own headquarters was also in Edinburgh with its four squadrons disposed as follows:
A Squadron: Dunbar
B Squadron: Edinburgh
C Squadron: Hawick
D Squadron: Edinburgh
899 joined on 6th January 1909
1095 joined on 22nd February 1910
1190 joined on 27th October 1911
1268 joined on 15th April 1912
1401 joined on 8th May 1913
1520 joined on 26th July 1914
1586 joined on 31st August 1914
1650 joined on 3rd September 1914
1859 joined on 21st October 1914
1844 joined on 7th November 1914
A 2/1st unit was formed in 1914 and 3/1st unit in April 1915. Both these second and third line units shared their number sequence with the 1/1st.
I also offer a comprehensive, fast and cost-effective military history research service. Follow the link for more information.