Hugh Allan was born in 1810 at Saltcoats, Ayrshire, the second son of Captain Alexander Allan (1780-1854) of Saltcoats (a first cousin of the poet Robert Burns), by his wife Jean Crawford (1782-1856). Hugh's father had founded the already important Allan Shipping Line in 1815, connecting Scotland and Canada, but it was Hugh who developed it from Montreal and made it into the huge financial success which it is remembered for today.
One of Hugh's five brothers, Andrew Allan (1822-1901), followed him to Montreal in 1839 and later succeeded him as President of the Allan Steamship Line. Their eldest brother, James Allan (1808-1880) of Ashcraig House, Skelmorlie, ran the shore-based aspects of the business in Scotland. Another brother, Bryce Allan (1812-1874), ran the company in England, and later bought Aros House on the Isle of Mull in 1874, which his son, Alexander (1844-1927) succeeded to two months later and gave up the shipping business to devote his life to the running of the estate 
Hugh went to Canada in 1826, settling in Montreal, Lower Canada, where he worked as a clerk in a merchandising business. After ten years there, by now a partner in the company, he got a loan from his family back in Scotland and bought sailing ships and steamers, expanding the company's shipping business.
Allan became President of the Montreal Board of Trade in 1851 (remaining until 1854), using his position to help persuade the Canadian government to subsidize a regular mail ship from Montreal to London. His firm, Montreal Ocean Steamship Company (commonly the Allan Line), using sophisticated ships built in Clyde and political contacts, took control of the mail contract in 1856. The Allan Line also carried immigrants under government subsidy. He soon became the richest man in Canada with a personal estate estimated between to have been between six and ten million dollars.
Allan had interests in new communications technology, manufacturing, aand mining. In 1852, he became president of the Montreal Telegraph Company, ultimately selling MTC's "telephone plant" to Bell Telephone for $75,000. He also established coal mines in Nova Scotia and factories for textiles, shoes, paper, tobacco, and iron and steel in Central Canada.
Thanks to Quebec's support for railway construction, Allan expanded in that area. He created a syndicate to build the national railway, promised as a condition of British Columbia joining Confederation. To get the contract, he bribed Prime Minister Sir John A. Macdonald, suscribing over $350,000 for Macdonald's re-election campaign in 1872, but the Pacific scandal (and Macdonald's defeat) meant the plan fell through.
Hugh Allan was knighted by Queen Victoria in 1871, died in Edinburgh, of a heart attack after his wife's death, and was buried in Montreal.. Sir Hugh was one of the wealthiest men in the world at his death. The shipping line was passed on to his second son, H. Montagu Allan.
Ravenscrag, Sir Hugh's Montreal home built in 1863 
Ravenscrag, showing the conservatory 
The view from Ravenscrag in 1869 
Biography on Sir Hugh's father, with a picture of his brother James Allan (1808-1880)
Sir Hugh's brother, Andrew, in 1871 
Sir Hugh's brother's, Andrew's, carriage outside his home 
Full biography of Sir Hugh Allan