Letter 852: Libanius says Proclus is effectively a fourth envoy because his buildings and family influence bind him to Antioch.

When the envoys had already been chosen, a stranger asked one of the citizens how many they were. He said, "Three." I happened to be there, and though I heard him say three, I said that not three but four were serving as envoys. "How four?" he asked. Because, I said, long before the three of them, Proclus had been chosen by the very things he built in the city: roads, colonnades, baths, and marketplaces. A man must love his own labor; and love has a powerful way of persuading him to shrink from nothing for the beloved. It is a fine thing when the same man both wants to benefit us and has the power to do it. He has power in two forms, since he also has his father's strength. He will use both for us, restoring the council to its ancient vigor, so that the people's happiness may not be visible every evening only in the colonnade you built, with songs, but so that the council too may have the dignity you choose to give it.

1. Ἤδη τῶν πρέσβεων ᾑρημένων ἤρετό τίς τινα ξένος πολίτην, ὁπόσοι τινὲς εἶεν. ὁ δὲ ἔφησε· τρεῖς. ἐγὼ δὲ τοὺς τρεῖς ἀκούσας, καὶ γὰρ ἔτυχον παρών, οὐ τρεῖς ἔφην πρεσβεύειν, ἀλλὰ τέτταρας. 2. πῶς, ἤρετο, τέτταρες; ὅτι πολὺ πρὸ τῶν τριῶν ἔφην ᾑρέθη Πρόκλος ὑπ’ αὐτῶν τῶν ἐν τῇ πόλει παρ’ αὐτοῦ πεποιημένων ὁδῶν τε καὶ στοῶν καὶ λουτρῶν καὶ ἀγορῶν. φιλεῖν μὲν γὰρ ἀνάγκην ἔχει τόν γε αὑτοῦ πόνον, τὸ δὲ ἐρᾶν δεινὸν πεῖσαι μηδὲν ὀκνεῖν ὑπὲρ τῆς ἐρωμένης. 3. καλὸν δὲ τὸ τὸν αὐτὸν βούλεσθαί τε ἡμᾶς εὖ ποιεῖν καὶ δύνασθαι. δύναται δὲ δυνάμεως δυοῖν εἴδεσιν, ἔχει γὰρ δὴ καὶ τὸ τοῦ πατρὸς σθένος· οἷν ἀμφοῖν ὑπὲρ ἡμῶν χρήσεται πρὸς τὴν ἀρχαίαν ῥώμην τὴν βουλὴν ἐπανάγων, ὡς μὴ μόνον ἐν τῇ στοᾷ τῇ παρὰ σοῦ φαίνεσθαι τοῦ δήμου τὴν εὐθυμίαν ἑσπέρας ἑκάστης ᾄσμασιν, ἀλλὰ καὶ τῆς βουλῆς δι’ ὧν ἂν βουλῇ πρέπῃ.