Key concepts

How BerlinOne is designed, before going into detail.

The rest of the help explains how to do things. This page explains how things fit together: with it, the other pages read without guesswork.

It all starts with categories

BerlinOne does not hold one single great history. It holds categories: each one tells a topic, small or large — Quebec's Quiet Revolution, Leonard Cohen's albums, the history of your family.

A category is made of events. An event is a dated fact: a title, a description, a date, and whatever helps place it — a place, an image, sources. "Release of the album Songs of Love and Hate" is an event in the category devoted to Leonard Cohen.

A category is therefore like a history book on one topic, and its events like its dated pages. You read them, write them, share them: everything in BerlinOne happens category by category.

The timeline brings together what you follow

The timeline has no content of its own. Among the categories you follow, you choose up to five, and it places their events side by side on a single axis.

That is where BerlinOne gets interesting: follow both the Quiet Revolution and Leonard Cohen, and you see what was happening in Quebec while he was recording his albums. Two seemingly unrelated topics echo each other, because they share the same years.

To see a category on the timeline, you first follow it, then add it to the display. You follow your own, and you pick others from the public catalog, the showcase of categories their authors have made public.

A date also says what is known

The day of an event is not always known. Sometimes only the month, the year, or even the century. BerlinOne doesn't make you invent: every date has a precision, and the display respects it — "June 1944" rather than a false "June 1, 1944".

On the axis, though, the event has to go somewhere. BerlinOne places it in the middle of what is known: on the 15th for a month, on July 1 for a year. That way the possible error stays as small as it can be, in either direction.

An event is either a point in time — a single date, like a coronation — or a period, with a start and an end, like a war or a reign.

Not all events carry the same weight

Over centuries of history, not everything can be shown at once. Two settings help the timeline sort things out:

  • importance, from 1 (a detail) to 5 (a major turning point): you can hide what falls below a threshold, and when events crowd together, the most important comes first;
  • featured, which highlights an event, and which you can show on its own.

Each event also has a nature, which says what it is: a battle, an invention, a birth, an album release. You read it in its card, and it decides which anniversaries are emailed to you: you can, for example, receive only those of births and discoveries.

Anniversaries in your inbox

Like a person, an event has anniversaries. BerlinOne can remind you of them by email.

Not every anniversary is kept: only those that fall on a multiple of 5 years. An album released in 1976 turns 50 in 2026; a discovery made in 1926 turns 100 the same year.

Three things are needed to receive these reminders. First, you turn them on in your Preferences: they are off to begin with. Next, in each category you follow, you check the event natures that interest you, for example births in a category of biographies, or album releases in a music category. Finally, you choose when the reminder arrives: on the day, a few days before, on Monday or on the first of the month.

As long as no nature is checked, no email is sent. See Account and privacy.

Every category has an owner

Whoever creates a category is its owner. Only they edit it directly and decide who sees it:

  • private, it is visible to them alone;
  • shared, it stays private, but the people they invited see it too — handy for a family history;
  • public, it enters the catalog, and anyone can read it and follow it.

You can still contribute to someone else's category: you make a proposal — an event to add, a mistake to fix — and the owner accepts or rejects it. They keep control over what bears their name, and everyone can help.

And if they want nothing to move, even by mistake, they lock their category: no one changes anything in it, themselves included, until they lift the lock.

Reuse without copying

The same fact often belongs to several histories. The fall of the Berlin Wall matters as much to the history of Germany as to that of the Cold War.

Rather than copying it, you add an alias to your category: a pointer to the event in another public category. It shows in yours like the others, but its content stays the original's — fixed there, it is fixed in yours too. And if the original disappears, or its category leaves the catalog, the alias disappears with it.

Where things happen

  • The portal is the front door: you search there, read the news, and find the way into everything else.
  • The timeline is for exploring: you move through time there, around an observation date.
  • The Studio is for organizing: the categories you follow, your own, the public catalog, and the events of each category.
  • The quick preview is the card of an event or a category, which opens over the page so you can read it without leaving.

AI, when you ask for it

BerlinOne can write with you. The BerlinOne Lab creates a complete category in conversation: you describe an idea, the AI proposes, you correct. In an event, Enrich looks for an image and sources. And on the timeline, AI Flash adds, for you alone, a few events around the period you are looking at.

You can also connect your own assistant — Claude, for example — to BerlinOne, and ask it questions about your categories: "what do I have on Quebec cinema?". The connection goes through MCP, short for Model Context Protocol: an open standard that lets an AI assistant read information from an application. It is read-only — the assistant reads, it changes nothing — and it is the MCP Read option of the paid plans. See Connect your assistant.

These features use AI credits. A paid subscription gives you some every month; the Free plan receives them once, on arrival — enough to create one category with the Lab. What you didn't ask for costs nothing: translations are automatic and free — you write in your language, BerlinOne translates into the other two — and so are suggestions.

Going further