Is it a coincidence that the titles of the House of Orange-Nassau fit almost perfectly to the Ancient Roman 'limes' in the Netherlands?
Read for 'title' the possessions the House of Orange-Nassau - Monarch of the Netherlands since 1815 - had hunderds of years ago. At this present day only it's titles remain. Hardly any physical possession is left for them.
Limes? It's the ancient border defense system of Ancient Rome. The Netherlands was, between 83 and 260 AD, devided in a part that was inside and outside the Limes Germanicus. Beyond the border (latin 'limes) lived the others, the enemy.
Around 400 AD the Romans left the Netherlands. And what was left? Castella! Places where civilians and soldiers protected themselves against the "enemy". Somehow the "most important" (?) castella must have come into possession of the House of Orange-Nassau. Somehow. Step by step.
Source. Picture (left): B. Colenbrander, 'Limes Atlas' (2005) p.83. Picture (right): U. Buys, 'Enz. enz. enz.', p.8-9.