Ancient Library is up and running again including Dictionary of Greek and Roman Biography and Mythology by William Smith (1867).
Quintus Caecilius Metellus Pius, thus cognomated because of his love for his exiled father Quintus Caecilius Metellus Numidicus, is featured in the early volumes of Colleen McCullough's Masters of Rome series, nicknamed The Piglet.
Smith's Dictionary, apart from a short piece on the Gens Caecilia, devotes a lot of space to the Caecilii Metelli, who, like so many republican Roman family branches, can be rather confusing.
CAECILIA GENS, plebeian; for the name of T. Caecilius in Livy (iv. 7, comp. 6), the patrician consular tribune in B.C. 444, is a false reading for T. Cloelius. A member of this gens is mentioned in history as early as the fifth century B.C.; but the first of the Caecilii who obtained the consulship was L. Caecilius Metellus Denter, in 284. The family of the Metelli became from this time one of the most distinguished in the state. Like other Roman families in the later times of the republic, they traced their origin to a mythical personage, and pretended that they were descended from Caeculus, the founder of Praeneste [CAECULUS], or Caecas, the companion of Aeneas. (Festus, s. v. Caeculus.) The cognomens of this gens under the republic are BASSUS, DENTER, METELLUS, NIGER PINNA, RUFUS, of which the Metelli are the best known : for those whose cognomen is not mentioned, see CAECILIUS.
METELLUS, the name of a noble family of the plebeian Caecilia gens. This family is first mentioned in the course of the first Punic war, when one of its members obtained the consulship; and if we are to believe the satirical verse of Naevius,—Fato Metelli Romae fiunt Consules,—it was indebted for its elevation to chance rather than its own merits. It subsequently became one of the most distinguished of the Roman families, and in the latter half of the second century before the Christian era it obtained an extraordinary number of the highest offices of the state. Q. Metellus, who was consul b. c. 143, had four sons, who were raised to the consulship in succession; and his brother L. Metellus, who was consul B.C. 142, had two sons, who were likewise elevated to the same dignity. The Metelli were distinguished as a family for their unwavering support of the party of the optimates. The etymology of the name is quite uncertain. Festus connects it (p. 146, ed. Müller), probably from mere similarity of sound, with mercenarii. It is very difficult to trace the genealogy of this family, and the following table is in many parts conjectural. The history of the Metelli is given at length by Drumann (Geschichte Roms, vol. ii. pp. 17-58.)
As shown above, the Metelli were a prolific family and indeed take up about 10 pages in the Dictionary, covering thirty of them, beginning with L. Caecilius Metellus, consul B.C. 251. They seem to have disappeared shortly after the assassination of Caesar, with an anonymous Metellus mentioned as having fought in with Mark Antony at Actium:
“There was a Metellus who fought on the side of Antony in the last civil war, was taken prisoner at the battle of Actium, and whose life was spared by Octavian at the intercession of his son, who had fought on the side of the latter. (Appian, B. C. iv. 42.) The elder of these Metelli may have been the tribune of B.C. 49; but this is only conjecture.”
Of course, there is also Decius Caecilius Metellus, the sleuth in John Maddox Roberts' SPQR mystery series, the only survivor of his family into Augustus' reign, but he is purely fictional.
The above coin image (scroll down on page) is courtesy of fellow blogger Ed Flinn and represents an AR denarius, Q. Caecilius Metellus, Roman Republic. 130 BCE. Helmeted head of Roma right, Q·METE downwards behind, XVI monogram beneath chin | Jove in quadriga right, holding branch in right hand, thunderbolt and reins in left, ROMA in exergue.
On Metellus Pius, the Dictionary has this to say:
19. Q. Caecilius Q. F. L. N. Metellus Pius, son of Numidicus [No. 14], received the surname of Pius on account of the love which he displayed for his father when he besought the people to recall him from banishment, in B.C. 99. He was about twenty years of age when he accompanied his father to Numidia in B.C. 109. He obtained the praetorship in B.C. 89, and was one of the commanders in the Marsic or Social War, which had broken out in the preceding year. He defeated and slew in battle Q. Pompaedius, the leader of the Marsians in B.C. 88. He was still in arms in B.C. 87, prosecuting the war against the Samnites, when Marius landed in Italy and joined the consul Cinna. The senate, in alarm, summoned Metellus to Rome; and, as the soldiers placed more confidence in him than in the consul Octavius, they entreated him to take the supreme command shortly after his arrival in the city. As he refused to comply with their request, numbers deserted to the enemy; and finding it impossible to hold out against Marius and Cinna, he left the city and went to Africa. Here he collected a considerable force and was joined by Crassus, who had also fled thither from Spain, but they quarrelled and separated shortly afterwards. In B.C. 84 Metellus was defeated by C. Fabius, one of the Marian party. He therefore returned to Italy, and remained in Liguria; but hearing of the return of Sulla from Asia in the following year (B.C. 83), he hastened to meet him at Brundisium, and was one of the first of the nobles who joined him. In the war which followed against the Marian party, Metellus was one of the most successful of Sulla's generals. Early in B.C. 82, Metellus gained a victory over Carrinas, near the river Aesis in Umbria, defeated shortly afterwards another division of Carbo's army, and finally gained a decisive victory over Carbo and Norbanus, near Faventia, in Cisalpine Gaul.
In B.C. 80, Metellus was consul with Sulla himself. In this year he rewarded the services of Calidius, in obtaining the recall of his father from banishment, by using his influence to obtain for him the praetorship. In the following year (B.C. 79), Metellus went as proconsul into Spain, in order to prosecute the war against Sertorius, who adhered to the Marian party. Here he remained for the next eight years, and found it so difficult to obtain any advantages over Sertorius, that not Metellus only was he obliged to call to his aid the armies in Nearer Spain and in Gaul, but the Romans also sent to his assistance Pompey with proconsular power and another army. Sertorius, however, was a match for them both; and when Metellus, after frequent disasters, at length gained a victory over Sertorius, he was so elated with his success, that he allowed himself to be saluted imperator, and celebrated his conquest with the greatest splendour. But Sertorius soon recovered from this defeat, and would probably have continued to defy all the efforts of Metellus and Pompey, if he had not been murdered by Perperna and his friends in b. c. 72. Metellus returned to Rome in the following year, and triumphed on the 30th of December.
In B.C. 65, Metellus was one of those who supported the accusation against C. Cornelius. He was pontifex maximus, and, as he was succeeded in this dignity by C. Caesar in B.C. 63, he must have died either in this year or at the end of the preceding. Metellus Pius followed closely in the footsteps of his father. Like him, he was a steady and unwavering supporter of the aristocracy; like him, his military abilities were very considerable, but not those of a first-rate general, and he was unable to adapt himself or his troops to the guerilla-warfare which had to be carried on in Spain; like his father, again, his personal character contrasted most favourably with the general dissoluteness of his contemporaries; and lastly, he imitated his father in the patronage which he bestowed upon Archias and other poets. His conduct at the time of his father's banishment, and the gratitude which he showed to Q. Calidius, are especially deserving of praise. He adopted the son of Scipio Nasica, who is called in consequence Metellus Pius Scipio [No. 22]. (Sall. Jug. 64; Appian, B. C. i. 33, 53, 68, 80-91, 97, 103, 108-115; Aurel. Vic. de Vir. III. 63; Oros. v. 18, 28; Plut.: Mar. 42, Crass. 69, Sertor. 12-27; Liv. Epit. 84, 91, 92; Vell. Pat. ii. 15, 28-30; Dion Cass. xxvii. 37; Plut. Caes. 7; Cic. pro Arch. 4, 5, 10, pro Planc. 29, pro Cluent. 8, pro Balb. 2, 22; Ascon. in Cic. Corn. p. 60, ed. Orelli.)
JSTOR (limited access) has
Symbols of the Augurate on Coins of the Caecilii Metelli, Lily Ross Taylor, American Journal of Archaeology, Vol. 48, No. 4 (Oct., 1944), pp. 352-356, NOTE: This article contains high-quality images.
Pompey, Metellus Pius, and the Trials of 70-69 B. C.: The Perils of Schematism, Erich S. Gruen, The American Journal of Philology, Vol. 92, No. 1 (Jan., 1971), pp. 1-16
The Siege of Rome in 87 B.C., Barry R. Katz, Classical Philology, Vol. 71, No. 4 (Oct., 1976), pp. 328-336