ArticleslgStudy

science

Lustrum

Lustrum is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Lustrum rather than just read about it. In short: A lūstrum (IPA: [ˈluːs̠t̪rʊ̃ˑ], plural lūstra) was a term for a five-year period in Ancient Rome. It is distinct from the homograph lustrum ( LUSS-trəm): a haunt of wild beasts (and figuratively, a den of vice), plural lustra ( LUUS-trah).

Lustrum — main illustration
Lustrum — illustration

Key takeaways

  • Lustrum belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Lustrum to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Lustrum from memory before moving on to harder problems.

Reference excerpt

A lūstrum (IPA: [ˈluːs̠t̪rʊ̃ˑ], plural lūstra) was a term for a five-year period in Ancient Rome. It is distinct from the homograph lustrum ( LUSS-trəm): a haunt of wild beasts (and figuratively, a den of vice), plural lustra ( LUUS-trah).

History The lustration was originally a sacrifice for expiation and purification offered by one of the censors in the name of the Roman people at the close of the taking of the census. The sacrifice was often in the form of an animal sacrifice, known as a suovetaurilia. These censuses were taken at five-year intervals, thus a lūstrum came to refer to the five-year inter-census period. Lustrum (from luo) is a lustration or purification of the whole Roman people performed by one of the censors in the Campus Martius, after the taking of the census was over. As this purification took place only once in five years, the word lūstrum was also used to designate the time between two lustra. The first lūstrum was performed in 566 BC by King Servius, after he had completed his census, and afterwards it is said to have taken place regularly every five years after the census was over. In the earliest period of the republic, the business of the census and the solemnities of the lūstrum were performed by the consuls. The first censors were appointed in 443 BC, and from this year down to 294 BC there had, according to Livy (X.47), only been 26 pairs of censors, and only 21 lustra, or general purifications, although if all had been regular, there would have been 30 pairs of censors and 30 lustra. Sometimes the census was not held at all, or at least not by the censors. The census might take place without the lūstrum, and indeed two cases of this kind are recorded, in 459 and 214 BC. In these cases, the lūstrum was not performed because of some great calamities that had befallen the republic. The time when the lūstrum took place has been calculated. Six ancient Romulian years, of 304 days each, were, with the difference of two days, equal to four solar years of 365 days plus one leap year of 366 days; the six ancient years made 1824 days, while the five solar years contained 1826 days. The lūstrum, or the great year of the ancient Romans, was thus a cycle, at the end of which, the beginning of the ancient year nearly coincided with that of the solar year. As the coincidence, however, was not perfect, a month of 24 days was interposed in every eleventh lūstrum. It is highly probable that the recurrence of such a cycle or great year was, from the earliest times, solemnized with sacrifices and purifications, and that King Servius did not introduce them, but merely connected them with his census, and thus set the example for subsequent ages, which however, as we have seen, was not observed with regularity.

See also Lustratio Decade Century Millennium

References

External links

Livius.org Lustrum

Worked examples

Example 1 — a first encounter with Lustrum

Start with the simplest possible case. Write down what Lustrum claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Lustrum before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Lustrum ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Lustrum

In research
Lustrum appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Lustrum in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Lustrum is common in secondary-school and first-year university syllabi. It links to neighbouring topics Population, Quinquennial events, Society of ancient Rome, so understanding it makes those chapters shorter.
In everyday life
Look for Lustrum outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Lustrum in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Lustrum means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Lustrum out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Lustrum in simple terms?

A lūstrum (IPA: [ˈluːs̠t̪rʊ̃ˑ], plural lūstra) was a term for a five-year period in Ancient Rome. It is distinct from the homograph lustrum ( LUSS-trəm): a haunt of wild beasts (and figuratively, a den of vice), plural lustra ( LUUS-trah).

Why does Lustrum matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Lustrum?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Lustrum.

Tags

  • Population
  • Quinquennial events
  • Society of ancient Rome
  • Units of time

Keep exploring