I got to know him in the 1999-2009 period, from when I first arrived in Brussels as a thinktanker on Balkan issues up to his time as Marti Ahtisaari's deputy in the Kosovo final status process. We saw each other often at conferences and I enjoyed learning from his vast experience. (Which included serving as Kurt Waldheim's chief of staff at the United Nations.)
We both attended our friend Mabel Wisse Smit's wedding to (the tragically short-lived) Prince Friso of the Netherlands, and I asked him then if this was the first royal wedding he had attended. He gave me a slightly odd look, and replied, "You could say that." I was a bit puzzled, because most people would be able to give an unambiguous yes-or-no answer to that question.
So I did a little research, and discovered that Albert had presumably attended both of his own weddings. The next time I saw him, at a conference in Ljubljana, I said to him, "So, you're a prince, then!" He replied, "Well, technically, yes, but the Republic of Austria does not recognise the title or permit me to use it." Which explains the ambiguity of his previous answer.
That was quite a memorable trip to Ljubljana. Albert and I came in on the same flight from Vienna and he was met by the Austrian ambassador who kindly let me take the spare seat in the car. As we drove into Ljubljana, the subject of the Monument to the Unknown French Soldier came up, and the ambassador excitedly asked the driver to detour so that we could admire it. It's quite a remarkable historical statement.
We all got out of the car to contemplate it silently. Who, you may ask was the Unknown French Soldier defending Slovenian liberty *from*? The Austrian diplomats knew perfectly well, and so did I.
Born under Schuschnigg's struggling government to an Austrian father and Hungarian mother in 1936, Albert devoted his career to overcoming the divisions of the past, and I think he succeeded more than most.
We will miss him.