Liechtensteinisches Landesmuseum has created a special exhibition called 1712 - Das Werden eines Landes ("1712 - A country merges") where one through a series of documents, paintings and other valuable objects can learn the history of the purchase and of the key players.
In 1699 Prince Hans Adam I ("the Rich") had purchased the duchy of Schellenberg, which corresponds to the present-day Liechtenstein Unterland. As explained in the press release from Liechtensteinisches Landesmuseum, when both Vaduz and Schellenberg were bought, the Liechtenstein dynasty gained control of non-intermediate territories which were held directly under the imperial throne. The purchase enabled the princes to qualify for a seat and a vote in the Imperial diet of the Holy Roman Empire. In other words a foundation was laid for the later sovereign country of Liechtenstein.
I learned about the exhibition through the Liechtenstein Marketing's June 2012 newsletter, which arrived in my mailbox today. The exhibition opened already on 5 April this year and can be visited until 14 October. More details can be found in the said press release (there is a summary in English) with photos of several of the exhibition objects. Seems like a great exhibition! Unfortunately I will probably not be able to visit Liechtenstein this year. My only visit to the principality so far took place in May 2005. I will return with a blog article from my visit later on.
The portrait of Prince Hans Adam I shown above is displayed in the exhibition. The image is taken from the museum's press photo section.