historical drama with happy ending

• Love Like The Galaxy (split into 2 parts, total 56 episodes)
• Love Between Fairy and Devil
• Ashes of Love

Historical fantasy romance dramas with HE:

• +1 Love Between Fairy and Devil - Tagged as xianxia. 
• Back From the Brink - Tagged as xianxia.
• The Blue Whisper (Part 1 and Part 2) - Tagged as xianxia. 
• Lost Love in Times  - Tagged as xianxia. 
• The Legends - Tagged as xianxia. 
• A Familiar Stranger - Chinese historical drama with limited bits of magic.
• Alchemy of Souls (Part 1 and Part 2) - Korean historical fantasy with magic.
• Splash Splash LOVE - Time travel. 
• The Romance of Tiger and Rose - Time travel / it's all a shared dream. 
• Dreaming Back to the Qing Dynasty - Time travel. 
• The Eternal Love (Part 1 and Part 2) - Tagged as wuxia. Also has time travel. 
• Who Rules the World - Tagged as wuxia. 
• Sound of the Desert - Tagged as wuxia.
• The Romance of Hua Rong - Tagged as wuxia. 

Historical dramas with a HE but no fantasy elements:

• +1 Love Like the Galaxy (Part 1 and Part 2)
• The Story of Ming Lan
• Story of Yanxi Palace
• Zhang Gong Zhu Zai Shang
• My Sassy Princess
  
• Love in the Moonlight
• The King's Affection
• Sungkyunkwan Scandal
• The Crowned Clown
• The Princess's Man
• The Tale of Nokdu
• Rookie Historian Goo Hae Ryung
• The King in Love

Edit: Kyle is correct. For all the dramas above with a Part 1 and a Part 2, the Part 1 does not have a happy ending. Only Part 2 has a happy ending. 

An Oriental Odyssey 
Dance of the Phoenix 
Dance of the Sky Empire 
Prince of Lan Ling 
Princess Pearl 
Princess Silver 
The Blooms at Ruyi Pavilion 
The Great Ruler 
The Legends 
The Romance of Tiger and Rose 
The Untamed 

 ItsU:

prince of lan ling has HE/SE?

It has a very tragic ending with a main character death. 

 ItsU:

that's the reason i skipped the drama 

Totally fair reason. It was done in a way that felt totally unnecessary and unsatisfying to me. It's the main reason I gave the drama a pretty harsh rating (6/10) even though there were other parts that I liked.