These voluntary contributions were frequently very large. Sometimes the more wealthy citizens voluntarily undertook a "trierarchy", or the expenses of equipping a trireme. We read that the freedman Pasion furnished 1000 shields, together with five triremes, which he equipped at his own expense. Chrysippus presented a talent to the state, when Alexander the Great moved against Thebes during the Battle of Thebes; Aristophanes, son of Nicophemus gave 30,000 drachmae for an expedition against Cyprus; Charidemus and Diotimus, two commanders, made a free gift of 800 shields; and similar instances of liberality are mentioned by German classical scholar August Böckh, from whom the preceding examples have been taken.