Cremation or Inhumation?

During the Ptolemaic period a distinctive type of subterranean tomb for multiple burials proliferated in the cemeteries around the city of Alexandria. Underground chambers cut into the living rock radiated from a central courtyard open to the sky. Most chambers contained a number of loculi, long narrow niches cut into the walls, which served as burial slots. Some loculi were sealed with painted limestone slabs in the form of small shrines. - Metropolitan Museum of Art

Roman columbaria were often built partly or completely underground as well. Most columbaria were managed by funeral societies and used by the lower and middle-classes. Niches could be quite simple or elaborately decorated with inscriptions, paintings, and mosaics depending on each family's economic means.  

The Columbarium of Pomponius Hylas is a 1st-century CE Roman columbarium, situated near the Porta Latina on the Via Appia, Rome, Italy. It was discovered and excavated in 1831 by Pietro Campana. Though its name derives from Pomponius Hylas, who lived in the Flavian period (69-96 CE), the building itself has been dated to between 14 and 54 CE due to inscriptions on two of its niches (one dedicated to a freedman of Tiberius and the other to a freedman of Claudia Octavia, daughter of Claudius and Messalina). It was later bought by Pomponius Hylas for himself and his wife.

 Inhumation was practiced regularly in archaeic Rome although cremation was gaining acceptance and a practice known as os resectum ("cut-off bone") was developed to satisfy both economy and spiritual traditions. According to Plutarch, King Numa Pompilius (r. 715-673 BCE) had forbidden cremation so perhaps in at least partial obedience to this prohibition, and perhaps on the understanding that "a part implies the whole", a complete finger was sometimes cut from the corpse before cremation and buried separately, unburnt, to complete the household's purification, return the deceased to mother Earth and make the grave inviolable. 

But, cremation became the most common burial practice in the Mid- to Late Republic and the Empire into the 1st and 2nd centuries. Interestingly, this appears to correspond to the military expansion of Rome and the increasing lack of ability to return intact war dead from distant battlefields.

Patrician members of the gens Cornelia seem to have resisted this change, though, and continued inhumating their dead until the first century BCE. In 79 BCE, the dictator Sulla was the first patrician Cornelius to be cremated, perhaps because he feared his body would be defaced by his former enemies.

Eventually, however, cremation remained a feature of imperial deification funerals, and very few others.  Building columbariums was finally halted during Hadrian’s rule from 117 to 138 CE as inhumation once more preferred.

Painted limestone funerary slab with a man controlling a rearing horse, 2nd half of 3rd century B.C.E. at the Metropolitan Museum of Art in New York. Here, a lively depiction of a Thessalian man named Pelopides trying to bridle a horse, while a boy stands behind him, commemorates a man from Thessaly in Northern Greece, who must have been one of the many foreigners who congregated in the wealthy, cosmopolitan Ptolemaic capital.

Painted limestone funerary slab depicting a soldier and two girls from Alexandria, 2nd half of 3rd century BCE at the Metropolitan Museum of Art.

Painted limestone funerary slab with a soldier taking a kantharos from his attendant girls from Alexandria, 2nd half of 3rd century BCE at the Metropolitan Museum of Art.

Painted limestone funerary slab with a soldier standing at ease, 2nd half of 3rd century B.C.E. at the Metropolitan Museum of Art. A soldier wearing a long blue cloak stands alone, with a spear in his right hand and a tall ovoid shield at his left. Celtic groups from Europe migrated eastward in 279 B.C. and established independent kingdoms in Thrace and central Asia Minor. Known as Galatians, they were used extensively as mercenary soldiers. Inscriptions identifying at least three Galatian soldiers who must have served under the Ptolemies occur on loculus slabs in a rather simple tomb found in 1884.

Interior of the Columbarium of Pomponius Hylas (Rome, Italy) courtesy of Wikimedia Commons contributor Tyler Bell.