Combining tables while changing id - SQL

I'm trying to create a search function in different tables using UNION and what happened is that the id's are duplicating making the search go wrong. How can I merge different tables into one while no id's are in common?

Here is the example

table1

id    name    desc
1     henry   post
2     albert  doth
3     jun     cloth

table2

id    name    desc
1     kin     revenge
2     pot     eve

The result SHOULD be like this

id    name    desc
1     henry   post
2     albert  doth
3     jun     cloth
4     kin     revenge
5     pot     eve

Please help me. Thanks.