Early and personal life
Born on Valentine's Day, 1945, the eldest son of Prince Franz Josef II and Princess Gina, Hans-Adam completed primary school in the Liechtenstein capital of Vaduz, before attending secondary schools in Austria and in Switzerland. A training stint at a London bank followed, before he enrolled on a business and economics course at Switzerland's St Gallen College, from which he graduated in 1969.
On July 30, 1967, the prince married Countess Marie Kinsky von Wchinitz und Tettau, a Prague-born industrial designer who studied applied art in Munich. The couple would later have four children Crown Prince Alois in 1968, followed by Maximilian in 1969, Constantin in 1972, and the youngest, Princess Tatjana, in 1973.
A financial wizard, Hans-Adam was just 27 when he was entrusted by his father to run the family's vast fortune, which today is estimated to stand at $2 billion.
Ascension to the throne
And while Hans-Adam did not officially begin his reign until after his father's death in 1989, the monarchy's extensive executive powers were transferred into his hands in August 1984. The ageing Franz Josef continued as head of state, but retained only a symbolic role.
Once on the throne, Hans-Adam worked diligently towards his long-time goal of having Liechtenstein admitted to the United Nations, and one year after his coronation, in 1990, the tiny country became the 160th - and smallest - member of the UN. The prince has since cited this event as his greatest achievement.
In 2003 he achieved further success by gaining a resounding mandate from his subjects, when they voted in a constitutional referendum to increase his political control over their country.
He has retained Franz Josef's tradition of inviting the principality's 32,000 subjects up to the castle for refreshments on Liechtenstein's national day and is said to often jog barefoot in its surrounding woodland to relax.
A one-time ski host to King Charles, Hans-Adam is also a keen deep-sea diver and a science fiction and archaeology buff.
The political and economic visionary's interest in his family's art collection, which contains over 1,000 works by masters including Rubens and Van Dyck and is valued at £300 million, is purely financial, however. "Personally," he says, "I tend more toward modern art."