My main focus was also Roman history, since I had my grandpa, who was like a personal teacher for me(courtesy/because) of grandpa. He was my greatest mentor. My main focus was also Roman history, (courtesy/because) of grandpa. He was my greatest mentor.

My main focus was Roman history, since I had my grandpa, who was like a personal teacher for methe catalyst. My main focus was Roman history, since I had my grandpa, who was the catalyst.

Catalytic is a constructivist teaching style which is less vague and is an explanation.

But my curiosity did not stop there: I read some books about medieval history that made , and became so interested in that era too. But my curiosity did not stop there: I read some books about medieval history, and became so interested in that era too.

My grandfather was (passionate about history), and beingspending time with him on that trip was such a blessing because he taught me everything he knew about (Italian history). My grandfather was (passionate about history), and spending time with him on that trip was such a blessing because he taught me everything he knew about (Italian history).

The word history gets a little repetitive by the end of this sentence, maybe try using other forms of the same word (e.g. obsessed about his historical passions). For Italian history you could be more specific or point out what you found interesting (e.g. Italy and their origins in xyz // Italian revolution)

I began to learn about them and how many of their story wasies were connected or caused something that affected others later on. I began to learn about them and how many of their stories were connected or caused something that affected others later on.

I began to learn about them and how many of their story wasies were connected , and/or caused something that affected others later on. I began to learn about them and how many of their stories were connected, and/or caused something that affected others later on.

And/or is a real word.

I think history is fascinating, and it makes you knowunderstand why things are the way they are today. I think history is fascinating and it makes you understand why things are the way they are today.

I think history is fascinating, and it makes you knowit explains and can lead to knowledge of why things are the way they are today. I think history is fascinating, it explains and can lead to knowledge of why things are the way they are today.

I wouldill always recommend people to read about history, any timregardless of the period, or a historical figure they are interested in. I will always recommend people to read about history, regardless of the period or historical figure they are interested in.

would is used when you have an uncertain future. Will is more appropriate since you're not going to change your behavior in the future.

I would always recommend people to read aboutthe history, of any time period, or about any historical figure they are interested in. I would always recommend people to read the history of any time period, or about any historical figure they are interested in.

Famous people like Saladin, Charlemagne, Barbarossa, and many others captured my attention. Famous people like Saladin, Charlemagne, Barbarossa, and many others captured my attention.

stay in the past tense since you're still speaking of the past

After that trip, my love for history started in anbecame obsessive way. After that trip, my love for history became obsessive.

After that trip, my love for history started in anhistory, which I now love, was my obsessive wayon. After that trip, history, which I now love, was my obsession.

Once I was back home, I started tochanging what I buy. books, games, and everything, all history related. Once home, I started changing what I buy. books, games, and everything, all history related.

IWhile it wasn't my first time in Italy, but itthis was the first time I started to acknowledge how full of history thate country is. While it wasn't my first time in Italy, this was the first time I started to acknowledge how full of history the country is.

This is a prepositional phrase so we can do it with while and not but. And it's interesting it helps the previous sentence. That/The is a matter of emphasis and here I think to emphasize the word country instead of the word Italy.

My love for history began when I traveled for the first time, newly along with my grandparents, to Italy. My love for history began when I traveled, newly along with my grandparents, to Italy.

for the first time is connected as if you mean this to Italy. It's an uncommon sentence but saying newly works nice.