Turkeys have been eaten in the Americas for hundreds of years (as that's where turkeys come from). So how did a bird from the Americas come to be the main Christmas meal for many countries around the world?
Turkeys first arrived in Europe, to Spain in 1519; and the first turkey was brought to the UK in 1526 by a sailor called William Strickland. (In 1550 he was given a coat of arms featuring a turkey on it!) It's thought that the first British King to eat a turkey was King Henry VIII.
No one is quite sure why turkeys are called turkeys! There are two main theories (and both or a combination of them could be correct!).
One theory says that the first settlers in the Americas thought that turkeys were a type of large guinea fowl (a bird from Africa which they would have been used to eating in Europe). Guinea fowl were imported in Europe by Turkish traders in Constantinople (now called Istanbul). Back then anything 'exotic' often had the word 'Turkish' or 'Turkey' put in front of it because the items often came through/via the country of Turkey. Guinea fowls were often called 'Turkey coqs' or 'Turkie Hennes' (both meaning 'Turkish/Turkey birds'), which became shortened to 'Turkeys' and so they gave the same name to the new bird they saw in the Americas!
Another theory is that, although turkeys originally came to Europe into Spain, they were mainly imported into Europe via the Turkish traders in Constantinople. So they were known as 'Turkey coqs'. And again over time, they also just became known as 'Turkeys'.
But in some countries, turkeys aren't called turkeys. In French they're called 'dinde' (meaning 'from India'), in Russian 'Indjushka' and Polish 'Inyczka' (both meaning 'bird of India'), in Arabic they're called 'diiq Hindi' (which means 'Indian rooster'), and in Turkish just 'Hindi' ('India')! The name was connected with India because Christopher Columbus was looking for India when he found the Americas and so an 'Indian' name was connected with the bird from the Americas.
In 1758 Turkeys were given an 'official' Latin name 'Meleagris gallopavo'. But that name is a mixture of Latin and Greek and actually means 'guinea-fowl chicken-peacock', which is VERY wrong as turkeys are not guinea-fowl, chickens or peacocks!
In Portuguese, a turkey is called a 'peru' - named after the country of Peru - which in the Americas. This might be the most sensible name for turkeys!
By 1720 there were about 250,000 turkeys being farmed every year in Norfolk (on the east coast of England in the UK). As well as coming via Turkey/Constantinople, turkeys also came into the UK from The Netherlands (which is quite near Norfolk by sea) via Spanish and Portuguese traders who had strong historical with The Netherlands/Holland.
Before turkeys could travel by train, they (and geese) had to be walked from the farms to the markets. This could take weeks, with the farmers/bird walkers and the birds having to camp each night at the side of roads! The feet of the birds were often dipped in tar to act like 'feet tires' to stop them getting sore! In the UK they would talk from Norfolk down to London and were only eaten by the rich at this time.
Turkeys became 'fashionable' to eat for Christmas in the UK after Queen Victoria first had a Turkey at Christmas (along with the more traditional Goose and Beef) in 1851.
The growing train network in the UK towards the end of the 1800s meant that turkeys could be moved much more quickly around the country. But it wasn't until after WWII, when farming became more efficient and so food cheaper, that turkey became the 'traditional' Christmas meal in the UK.
Most commercially grown turkeys are now the 'White Holland' variety which was first breed in the The Netherlands/Holland.