 After his journey to Rome, where he was able to examine ancient monuments and consult unique manuscripts in the Vatican Library and other well-stocked private libraries (1568-1570), he returned to Louvain to continue his legal studies. Fleeing the political and religious conflict in the Low Countries, Lipsius went to visit his friend Carolus Langius (Charles de Langhe) in Liège (1571) — Langius would become Lipsius’s master of Roman Stoic philosophy in the dialogue De constantia.