There may be several facts there. I don't really have the time or inclination to check the math regarding dates. Even if the dates are all correct, though, that doesn't necessarily mean the conclusions are correct.

The sole purpose of the picture appears to be to justify the crusades. Was the Moorish conquest of Spain justification for marching on Jerusalem, for example? Seems to me that marching on Spain to drive the Moors out would make more sense, but they stayed in power for 400 years after the first crusade took place.

I think this is one of those cases where someone uses a little truth to tell a big lie. The argument appears to be that Muslims use the Crusades as evidence of their victimization by the West, even though those Crusades were brought upon themselves due to their attacking Christians first. It's a view of history wholly lacking in nuance.

This response in the FAQ may give you some more reasoned analysis of the facts.

People come to this sub asking about these sorts of claims every once in a while, whether it's graphics with lists of dates/events like this one, or maps, or videos. In addition to the FAQ post linked by /u/Quierochurros, it would be worth taking a look at this one:

• What is the consensus on Real Crusades History? - /u/jukeboxhero and /u/shlin28 review a YouTube video. The thread includes links to several other, more directly on-topic posts (including that FAQ post), all of which are highly recommended.

The posts have been archived by now, so if you have follow-up questions for any of the users, ask them here & include their username to notify them

While the obvious point of this image is a little silly, I'm somewhat curious about the claim that Muslims sacked Rome in 846. What is this referring to? I assume it's not 100% made-up or 100% true, but I'd like to know the details, anyone know? Did some Berber pirates attack it then or something?