Marshall Eriksen (Jason Segel) is Ted's college roommate and now best friend in How I Met Your Mother. Marshall is engaged to and eventually marries his college sweetheart, Lily.
Marshall is a lawyer who always wanted to work as an evironmental lawyer but in an effort to provide for his wife and future family now works with Barney at a big bank corporation.
Marshall was previously Ted's roommate for the first few seasons but now lives with Lily in their own condo they purchased.
Barney: Barney Stinson is back on the market. Mothers, lock up your daughters. Daughters, lock up your MILSWANCA's.
Ted: Oh wait, I can get this. Mothers I'd Like to Sleep With and Never Call Again
Barney: Correct, circle gets a square
Being in a couple is hard. And committing, making sacrifices, it's hard. But if it's the right person, then it's easy. Looking at that girl and knowing she's all you really want out of life, that should be the easiest things in the world. And if it's not like that, then she's not the one. I'm sorryMarshall