Politician and businessman. Born in Edinburgh, the son of Sir John Warrender (1786 - 1867), from whom he was to inherit the Baronetcy of Lochend, Warrender was educated in Eton then entered the Coldstream Guards, rising to the rank of Captain. Warrender was a successful businessman who fued his Bruntsfield estate to build the Marchmont district of Edinburgh from 1869. He served as a Member of Parliament and as a Deputy Lieutenant of both Edinburghshire (Midlothian) and Haddingtonshire (East Lothian). In 1854, he married Helen, daughter of Sir Hugh Purves-Hume-Campbell of Marchmont in London.