Как объединить 2 запроса в один?

`SELECT
	UserItems.name,
	UserItems.itemid,
	UserItems.price,
	UserItems.status,
	UserItems.userid,
	UserItems.timestamp,
	BoxItems.type as "type",
	BoxItems.img as "img",
	BoxItems.caseid as "caseid"
FROM UserItems
	LEFT JOIN BoxItems ON
		UserItems.itemid = BoxItems.itemid
WHERE userid = ?
GROUP BY UserItems.id
ORDER BY timestamp`

`SELECT
	HistoryItems.name,
	HistoryItems.itemid,
	HistoryItems.price,
	HistoryItems.status,
	HistoryItems.userid,
	HistoryItems.timestamp,
	BoxItems.type as "type",
	BoxItems.img as "img",
	BoxItems.caseid as "caseid"
FROM HistoryItems
	LEFT JOIN BoxItems ON
		HistoryItems.itemid = BoxItems.itemid
WHERE userid = ?
GROUP BY History.id
ORDER BY timestamp`